Hey guys, I know this isn't a Buick question, but hoping someone can help. A friend has a 71 GTO with a non original motor. He wants to find out if it came with a 400 or a 455. How can he go to get this figured out? Thanks, Chris
He can contact this person, and find out everything that his car came with originally. http://www.phs-online.com/
I don't believe that there is anything on the car that would identify it as 400 vs. 455. Probably would have to have it verified by Pontiac Historical. The instaled engine is not identified in a VIN until 72
Easiast to climb up under the '71 GTO on the rear driver side of the frame in front of the tailpipe hanger bracket. Along the outside of the lh rail frame will be a two letter code & a date. 1971 2door 350 Lemans & 400 GTO's received a frame with two letter code of CB. '71 T-37-LeMans-GTO's with factory 455's or 455HO's received a frame with 2 letter code of either HW or HX. These codes are not commonly known, so unless frame has been swapped, or frame is severely rusted, the frame code will help in telling if car was original 455 car. '70 & 72 455 cars had different two letter frame codes & above info will only work for '71 Pontiac A-bodys. Good luck. Roger
Roger, He checked his last night and he said it was "CR". He is absolutely positive it is not "CB". What does that mean? Thanks, Chris
Here is some more information that he provided: top line has a 3992388 S (with a circle around the s) 363 number below that is a 4 8 N1 CR designation
Chris, CB & CR are the '71 Pontiac 2door A-body unboxed 350-400 coded frames. I cannot remember which is auto & which is for stickshift application, but each should have different code. HW & HX are def only used in 455 & 455HO cars with unboxed frames. Will look at the frame code on my Judge at lunch & get reaquainted with the date coding process. Suffering from CRS syndrome today ou: Roger
