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1971 Cutlass SX - A Unique SX Uncovered

Alan Reedy | Published on 6/24/2020

1971 Cutlass SX - A Unique SX Uncovered - A 6,846 Mile Car

By: Alan Reedy  June, 2020

In December of 2019, I traveled 750 miles from Providence Rhode Island to Lexington North Carolina with a trailer in tow, to examine, document, and possibly purchase a 1971 Oldsmobile Cutlass Supreme SX Hardtop. The car was advertised in a Craigslist on-line ad as being part of an estate auction. The listing intrigued me because it was listed as being completely original with very low mileage. A few pictures of the car in the advertisement showed it to be beautiful Sterling Silver, with a black vinyl top, black bucket seat interior, with a dual gate shifter. What further intrigued me was the fact that the car was sporting the original SSII wheels, painted in the original argent color with purportedly, the original tires still on the car from the delivering dealer. To add to my interest was the fact that the car was not advertised as being part of a car auction but rather, it was part of an estate auction, held at the home of the elderly man who passed away. I stumbled across the Craigslist posting purely by accident. I placed a call to the phone number listed on the ad and it led me to the auctioneer. 

The auctioneer told me that the story he got was that the car is currently in the hands of the second owner. He said that he had spoke with the first original owner, and that he is hoping that the first owner will also be present at the sale. He relayed that the first owner and the second owner had both stated, that the car has never stayed a single night outdoors, that it has always been garaged, and that the car has never seen a drop of rain. He also stated that mileage of 6,846 miles is the correct mileage and that the car was only used for Sunday rides, weather permitting. He further informed me that the current owner has had the car for approximately 35 years, and that both owners stated that the car is still on the original tires that it came from the dealer with. He then ran down the list of options that were included on the car by reading the original window sticker to me over the phone. At the completion of our phone call, I told him that I would see him in a few days. Now keep in mind, the auction was scheduled for Friday, and my conversation with this auctioneer took place on Tuesday. I didn't have much time to waste. So I messaged a friend of mine and asked him if he wanted to take a road trip with me. He asked what it was about and when it was going to be. After I explained it to him, he said, I'm in, let's go get it. So I hooked up the trailer and we hit the road Thursday morning. The trip took me approximately 16 hours each way, included an overnight stay, and about $400 in tolls and gasoline cost.

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The SX as it was displayed for viewing at the sale.

I arrived at the auction site Friday morning about 1 1/2 hours before the car was to be auctioned off. There were a lot of cars and at least 3 other trucks with trailers in the parking area (field) of the sale, and a quick review of the license plates revealed no one had travelled as far as I had. The auction was already underway and there were about 200 people present bidding on all types of household items that were located in open garage bays and spread out onto numerous tables. The car itself was presented off to the side on a grassy area with only the hood open. Several people, who appeared to show interest in the car only, were looking it over and gathered around it waiting for its scheduled time to be sold. So I joined them.

The 1971 Oldsmobile Cutlass SX  at the sale.

After a quick 30 second glance at the overall vehicle, I noticed a couple of things that were not technically correct or original equipment for an SX. These were aside from a few general maintenance items which would be expected to be changed on any 48 year old car i.e. battery, exhaust pipes. I could however, immediately tell that it was a real survivor car, and that I had to dig into it a little bit further. I figured whether I bought this vehicle or not, I was not going to let the opportunity pass me by, and not document, the condition and details of such an original example.

The first thing that stood out to me as not being correct was that the car had the wrong rear bumper on it. Now most SX fans already know, that the SX is supposed to have the cutout bumper for the dual exhaust and trumpet tips similar to the 442. It is also the largest single thing on an SX that would even indicate the possibility of the car being an SX. Other than the rear bumper, the only other outward indicators of an SX would be the two small emblems located on the front fenders. There are no other external identifying features. Never the less, this car had the standard rear bumper without the cutouts, and the exhaust pipes turned down similar to what would have been used on any of the regular Cutlass models. More on this coming.

Note the standard Cutlass bumper. It does not have the exhaust cutouts and Trumpet Tips as an SX should. Also note the individual OLDSMOBILE letters spelled out across the trunk lid, which was new for 1971. The prior 1970 version had a CUTLASS script on the right side and a Rocket emblem around the trunk keyhole.

The second thing that stood out to me as being incorrect, were the tires. Although they were period correct Goodyear Polyglas, they were not the correct size that would come on an SX. In 1971 the standard tire for an SX would have been G-78-14. Had the car been ordered with the optional Wide-Oval tires, (either in Whitewall or Raised White Letters), the size of the tires would have been G-70-14. The tires present on this car that were proclaimed to be the original tires from the original delivering dealer, were H-70-14, one size larger than what was available from the factory. More on this later as well. 

H-70-14 tires are one size larger than the factory offered. Note that original SSII Wheels, Option N66, are painted "Argent" and not body color. Body colored wheels became available in 1971 and were named SSIII Wheels, and denoted as Option N67. Also note the proper acorn lug nuts which appear to have never been removed from the car.

When I go to examine a car, the first thing I set out to do is, verify that the car is actually a real SX. I'm one of those "Show me the numbers" kind of guys. So naturally, I go straight for the VIN number on the dashboard, and then directly to the VIN number on the engine block. Now keep in mind that this is not my car. This car is on display for sale, like it would be on display at a car show. I have to be cognizant of the fact that I have no right to touch this car. I can't be leaning on it, taking things apart, moving things around, wiping things off, etc. Thank god these new cell phones have great cameras in them and are very compact. They can and do, often assist us in seeing things that we would not normally be able to see with the naked eye. So I get going and start sticking my cell phone camera down into every little nook and cranny that I need to, to get to see what I need to see. I started taking pictures of things that most people would not even look at. In a perfect world, I try to capture the dash VIN number, cowl body tag, engine block VIN stamping, carburetor number, intake manifold casting, distributor number, transmission code and VIN number, frame number, rear end code, compliance statement VIN number, and a whole bunch of other little details that would just bore the crap out of most people. I succeeded in capturing as many of these details as I could with the car being presented as it was. 

Vehicle Identification Number (VIN) located on the dashboard. 342571M173148

With all the components in place, it's a little tricky to try and get the engine VIN stamping. Note the Big Block fender brace bolt just in front of the hood hinge. Also note that in 1971, similar to the L31 4 bbl engines in 1970, the air cleaner is the same "OI" Code unit that is used on the 350 4bbl engines. Only the W-32 in 1970 used the larger snorkel "OP" Code air cleaner.

As we go deeper into the engine compartment, we come across the correct for 1971 G heads. Also noticeable are the original exhaust manifold bolt locks. We need to get just below this bracket to be able to view the engine number

Even with all components in place, it's not impossible to get to the VIN, and there it is. 31M173148. The matching Big Block engine number to the dash VIN in 1971 is proof positive that the car is an SX.

Correct number carburetor for the 71 SX, 7041251. Note the build date of 0751 meaning March 16, 1971. The date code is broken down as follows. The first 3 digits indicate the number of the day within the year the carb was built. The last number indicates the year the carb was built. In this case the carb was built on the "075th”day of the year (March 16th), in the year "1"(1971).             

Fisher body tag, located under the hood on the top of the cowl (firewall), shows the Year (71), GM Division and Body Style (34257) Oldsmobile Cutlass Supreme Hardtop Coupe, the Plant assembled (LAN) Lansing, and the production sequence number (346675) of the Fisher body. Note that the Fisher body number does NOT, nor is it supposed to, relate to the vehicle identification number, (VIN). The next line shows the trim code (970) Black bucket seat interior, Paint code (13) Sterling Silver and the top color (B) Black vinyl top. Next line shows the build date (03D) which breaks down as follows. The first two digits indicate the month of the year the car was built (03 = March). The last letter indicates the week of the month the car was built (D = 4th week). Also on this line option B85 is indicated, which is the side window sill trim that was mandatory on all 1970-1972 Cutlass Supremes equipped with a vinyl top.

Note the factory inspection marks on the firewall.

Close up detail showing vinyl top trim, roof drip rail trim and the B85 window sill trim.

The car presented itself beautifully for an un-restored original.

Correct emblem placement for 1971. Note that the gap between the SX emblem and the Cutlass script emblem is smaller than on the 1970 models. This is due to the Script being different between the years.

Obviously, as the car was presented, it was impossible to get the details of the stampings and codes located on the undercarriage. I did however manage to get some pictures that show the general original features of the undercarriage. 

There’s the transmission tag. There’s no doubt in my mind that a slight wiping off of the road grime will reveal the 71-OD code. Also note the delivering dealer applied undercoating on the floorboards.

Obviously, as the car was presented, it was impossible to get the details of the stampings and codes located on the undercarriage. I did however manage to get some pictures that show the general original features of the undercarriage. The car is clean enough underneath that you easily read the NY code stamped into the standard lower control arm. Had this car been equipped with the FE-2 suspension, the control arm would be a boxed type unit to accommodate a sway bar, and stamped with the code NZ.

Note the rear axle posi-traction tag is attached to the bolt at the 5 o’clock position. Although not visible in this picture, the code stamped into the top right side of the axle tube is R3 representing the 2.56 gears.

Contrary to popular belief, not all SX’s got the rear frame reinforcement braces attached to the front bolt of the rear lower control arms, and this is an example of one. Factory Oldsmobile documents have conflicting information about this for 1971. The 1971 Product Information Manual states that these braces are to be included only on the 442 and L32 equipped cars (which this car is). The Parts book lists all the applications of this brace for all years, and makes no reference to it being included on any Cutlass Supremes in 1971. The parts book indicates for 1971, it was applied only to the 442 and other cars equipped with OAI. For a comparison reference, in 1970 it was common for early L33 2 bbl cars not to have these braces, as the original application was only for the performance engines including the W32 SX.  An application change took effect on January 30th 1970 which stated they were then to be included on all 455 equipped cars. Hence some L33 2bbl cars produced in February do have these reinforcement braces.

Once I crawled out from under the car, I asked someone if it was ok to open the doors and he pointed out the man who was the son of the owner. I walked over and introduced myself to the man and congratulated him on having such a fine automobile. He was a very friendly middle-aged gentleman and willingly opened up the car doors and the trunk for me to view them and take additional photos.

I could find no fault with the interior other than the floor mat being out of place.


The original compliance certificate dated March of 71. Note the original paint barely scraped off the latch.

Notice the condition of the weather stripping on the roof rail and the immaculate original upholstery.

It’s apparent that the chromed plastics have not had very much exposure to sunlight.

The whole time I was examining the interior and trunk, I was asking the son of the owner several questions about the cars history and some of the things I had noticed including the routine maintenance that was performed. He was well aware of everything I questioned of, and had the answers for everything, except the rear bumper and the tires. His statement regarding those two items was that he is absolutely sure, that they have not been changed since his father had owned the car. He expressed that the rear bumper and the tires are the ones that came on the car when his father bought it from the first owner.

The original spare tire and wheel is still mounted in place from the assembly line. Note that tires with markings on them from the warehouse were typically used as spares as they were not “clean” enough to be used on the outside of the car. Also note the color of the spatter paint and its coverage to include the trunk latch. 

Notice the nubs still on the tire, the original plating of the jack stand, the original green backed trunk liner, and the spatter paint being applied prior to the addition of the side marker lamps and exterior chrome trim.

Upon looking in the trunk, my suspicion of the tires not being original was confirmed. The spare tire mounted in the trunk was the original spare tire from the factory. It was a B F Goodrich Silvertown Belted G-78-14, and it was still mounted in the same position it was placed in on the factory assembly line. The overall appearance of the trunk looked as though it had never been opened before today to place the cars storage cover in. Some of the details in the trunk are worthy of noting.

The correct and original trunk decals are barely even wrinkled from any form of condensation. Note that the exact placement of these decals varies slightly from car to car as they were hand applied by whichever employee was working in that area on that particular day.

Note the as new condition of the trunk liner, the original paint coverage’s, the hardboard liner behind the seat, the springs in the seats, the wiring harnesses and retainer clips, and the single blue wire for the additional Bi-phonic speaker ordered separately for the AM radio.

After speaking with the son for several minutes during my inspection, and once I had completed taking the pictures I wanted, he brought me over and introduced me to his mother. She was the actual owner selling the car of her deceased husband.  She was also very friendly and had a great deal of knowledge about the car during their time with it. She explained to me that her husband was the second owner of the car, and that they knew the first owner who repeatedly tried to buy it back. She also stated that the car was treated like her husband’s cherished gem and he would not part with it. She confirmed what I had heard earlier, that the car has never once spent a night outdoors, was only driven on Sundays, and never once had been hit by a raindrop. When asked about the tires and the rear bumper, she also said that the tires on the car are the same ones that it came with when they bought it from the original owner. She also elaborated that the car had never had any major damage to it, and that the bumper had never been changed since they owned the car. 

Apparently from watching me, and over hearing some of my conversations with the owners and my friend, it became obvious to some of the others that I might know a little bit about this particular model of car. One fellow finally approached me and asked me, if I could tell if it was really a numbers matching car. I looked at him smiling and said, Oh Yeah! It’s Real! They all match! He said, that’s funny because three other guys looked at the body tag, and then at the VIN tag, and they all said they don’t match, it’s not a numbers matching car, and they all left. I just chuckled and said, Oh, so they’re not here anymore? LOL. I then briefly explained to him that those numbers are not supposed to match, that they are two different numbers that represent two different things. The car was just about to be auctioned off in a few minutes and I wasn’t there to try and discourage anybody from bidding on the car, so I said very little to anyone other than my friend about my personal observations.

Within a couple of minutes the auction of the car had gotten started. The auctioneer started by describing the terms of the auction to include that there was an undisclosed reserve on the car. He then continued with a description of the car and its owner history. He described that the original owner could not make it to the sale, but that he would provide the successful bidder with his contact information to answer any questions they may have about the car. The bidding started with the usual fanfare of the auctioneer trying to get the starting bid as high as he could, and then as usual, somebody kicked it off with a low ball bid. LOL. It didn’t take long for the ball to start rolling upwards from that point. The bidding was pretty active and I saw no reason to jump in at this point. I already had a number in mind in which I was willing to go up to, and they hadn’t reached my level yet. The bidding slowed down obviously as the amount rose higher and it was approaching my level very slowly. Finally it seemed to have reached a stalling point, and I was just about ready to throw my hat into the ring when the auctioneer announced that the reserve was off, and that the car will be sold here and now. As usual in this situation, that information sparked renewed interest in the bidding. Although it appeared there were only two serious bidders remaining, they slowly raised the sales price over the threshold of what I was prepared to spend causing me, never having to place a bid at all. 

When it was all said and done, I approached the buyer, introduced myself, and congratulated him on his purchase. I informed him that I am quite familiar with these models and if he ever had any questions about the particulars of the car, I would be more than happy to answer his questions the best I can. We very briefly discussed a couple of issues and I then proceeded to head back to my truck to start my drive home. While my friend and I were getting organized for the drive, the purchasers’ friend came by and I gave him my business card with my contact information on it. We then started on our long journey.

Having purchased the car, the new owner was presented with the original keys.

Remember when I said earlier there was more to come about the rear bumper and the tires?  Well here is where the answers came in. It was about an hour after I left the auction site, and I was probably about 60 miles into my trip already when my phone rang. I didn’t recognize the phone number and answered the call on my Bluetooth through my vehicle. It was the purchaser of the car who was also on his way home in a different direction, with the car loaded on his trailer. He informed me that after he got the car loaded up and started his drive home, he contacted the original owner from the contact information provided to him. He said the original owner was very happy to talk to him about the car and this is what he said.

The original owner told the purchaser, “Congratulations on buying that car. That is a beautiful car. I ordered that car from the factory and I ordered it to have everything just the way I wanted it. I loved that car so much. I was heartbroken when I had to sell it. I had it for 14 years and it only had 2,700 miles on it when I had to sell it because I was going through a very messy divorce. I regretted selling it all my life and I tried to buy it back several times, but the guy wouldn’t sell it back to me. Now I’m too old to take it back.  I have never driven that car in the rain, and it had never been left outdoors overnight. I always kept it in the garage and I always kept it clean. It was never damaged in any way”.

Now this is a good place for me to add this little tidbit of information. The purchaser of the car was not completely aware of the uniqueness of the SX model or its features. When I spoke with him after the sale, he did not believe me when I told him the car had the wrong rear bumper on it, and that an SX should have a cutout bumper and trumpet tips. He was confident that the bumper that was on the car was the correct one for the car. So when he was talking to the original owner on the phone, he simply asked if anything had ever happened to the rear bumper. He then explained to me that when he asked that question, the man lashed out, “Let me tell you something about that rear bumper! I was waiting for that car to come in every day, and I was at the dealership the day it finally came in. I was right there, and I watched them take it off the rail. One of the salesmen was standing near me and I told him right then and there, that car has the wrong back bumper on it! He said no sir that is not the wrong bumper. I was madder than hell and I argued with him and told him that, that car, is supposed to have the bumper with the exhaust tips coming through it. He kept saying I was wrong. I kept telling him, IT was wrong, and he finally went inside the dealership to check his paperwork. When he came back out, he apologized and said yes, it was the wrong bumper and they were very sorry for the mistake. He said that they would order the correct bumper and when it comes in they would change it for me for free. I told him, don’t bother, just give me the damn car, I’ll take it the way it is. Well I took the car home and I only had it for a couple of days before I decided it just didn’t look right. I didn’t care for look of the tires. They looked too small for the car. So I went back to the dealership and told them I want bigger tires put on it. They changed my tires to the bigger ones I wanted and those are the same tires that are still on that car today. They have never been taken off again”. 

So there you have it. Straight from the proverbial horses mouth. Completely unsolicited testimony which clearly and understandably addresses the two concerns I had with the authentication of this car. It just goes to show you two things. 1) Mistakes have been made in the assembly of our beloved vintage autos from the time they were born. Not everything is always perfect as it is supposed to be. And 2), Sometimes things get changed so early in a cars life, subsequent owners often think, that’s the way it’s always been, so that’s the way it came from the factory. 

Luckily in the case of this particular SX, we have clear and credible evidence of its originality. 

About the Author

Alan Reedy is one of the foremost knowledgeable experts on the particulars associated with the Cutlass Supreme SX.  He has been researching, restoring and advising on the technical features of the SX models since the early 1980’s. During that time, he was a Cutlass/442 technical advisor for the Eastern Mass GMO Chapter of the Oldsmobile Club of America. His SX at the time was the first ever to be featured in National magazine publications since the original road testing articles were written at the introduction of the SX model. To this day people still refer to those early articles as the first time they ever heard of or seen an SX. Alan is affiliated with the SX455 club, the SX Registry, and the website as an SX455 Guru and leading technical advisor for all things related to the 1970-1971 Oldsmobile Cutlass SX.

A printable PDF version of this article for dues paying SX455 members appears at the link below:  1971 Cutlass SX Revealed with 6,846 miles