General Cutlass SX455 Q&A

In the absence of any original dealer paperwork, you have pretty much ruled out everything that could possibly identify or document the car as an actual SX. The SX did not have a lot of unique features included on it to differentiate it from a Regular Cutlass Supreme ordered with a 455 engine. Being a Lansing car, it would also be void of any paperwork other than a broadcast card which may or may not be found inside, and even then it may not have the Y79 option listed on it. Since you know the numbers on the motor and trans, that should tell you what year they are from. The E heads are correct for the 1970 application. The rear end would also have no identifying information specific to whether or not it was in an SX. As Mr. Thompson said, we'd love to look at pictures of what you have.

Will be very hard to prove it is an SX unless you have paperwork. Please post pictures of the car.

i bought a 70 cutlas surpreme im pretty sure its an sx butt engine block trans and rear diff are not numbers matching.it has cutouts in rear bumper,front fender bracing and rear frame supports,along with proper placed badging.its a lansing car 2nd week of janurary.the heads are stamped e and have the 2 inch intake valves so im assuming it would be a 2 barrel car.heads have no markings or stamps that it was married to a particular car.what do you guys think?