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The official club for enthusiasts of the

1970 & 1971 Oldsmobile Cutlass Supreme SX


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Terry Divelbliss
Club President

Alan Reedy
Senior Tech Advisor
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Bob Peters
Founding President


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Olds Rants & Raves

Cutlass Supreme with 455
Ted Bowles
Joined to find out whether my Cutlass Supremem was a SX. Wanted to share. Found original build sheet under gas tank. Car originally came with L74 (350 4bbl) with a whole lot of options..

Were certain options exclusive to the SX only? ie A31 - power windows? N30 - delux steering wheel

The motor it has in it now - does not match the car - but the block unit number -39X1224A8 tells me it"s a 455 built in 1969 in Kansas City. The block date and the head date are built within 4 days of each other in November of that year. Has factory dual exhaust and OC69TH400 transmission. Car was built Aug 9 1969.

Is this car a cloned SX or an Olds Cutlass Supreme with a 455-400 transmission with some options?

Your feedback is appreciated. Thanks Ted   PS vin # is 342570Z100891 2 door hard top one color - was gold
SX455 Chat
All Cutlass SX cars were build with a 455. You could get a Cutlass Supreme with a 350 and just about every option found on an SX. It seems like you have a very nice car that was cloned into an SX.

Bob Peters
SX455 Club President
Ted Bowles
thanks bob ill keep you posted on my reasearch

ted bowles
Ted Bowles

Just wanted to let you know my conclusion. I've determined the car is a 1970 Olds Cutlass Supreme that was ordered with the L74 engine package - it came with a 350 HC V8 4bbl that had dual exhaust and was ordered with options that were also available on the SX. At some point in the car's history - earlier I suspect - a period 455 replaced the 350 and voila a SX clone was born. The car's frame and running gear's in great shape and it runs and drives perfectly. Based on this, I'm going to start to restore a car I wish I had in high school.

If anyone needs codes the were available on the Cutlas on 1970, let me know because I have the original build sheet from the Freemont plant.

Hi Ted, can you post or email me a pic of your car? I have a handful of '70 Supremes in the "registry files" that have 455s but are not SXes. Owners at the time of sale (Ebay, traderonline, etc.) claimed that they were original #s matching 455 cars, but who knows. Maybe yours is one of the gold ones I have and i can I can take one off the list. Thanks -
Ted Bowles
Terry- working on pics-couple of question s
-was the HC350 -QN- only available in 1970? can i still be a member if i have a clone?Did a ll 70 cutlasses have the bolt hole for the front fender support?- The neat thing with this car is it was 891 of 68000 produced-hope the pics help-will follow shortly-Ted
Ted Bowles
Here are the pics - 70 Olds Cutlass 455 - found the original 350HC (L74) that would have come originally with car - so I have the best of both.

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