Codes don't match

[jeff b]

Need some help with option codes on my 78 vette.Tank sticker lists M-20 as the tranny but the info I find on the internet says it should be M-21 Engine code is CHW but car currently has an auto tranny. How can I tell if it had a clutch pedal at one time? Thanks in advance for your help! P.S. this explains why the carb has no hookup for the kick down cable!

 

[JohnZ]

CHW is a base L-48 4-speed engine, and the only 4-speed available with that engine was the M20 wide-ratio (2.85:1 1st gear); the close-ratio M21 was only available with the L-82 engine. Does it have a tower welded on top of the driver's side frame rail about 6" aft of the steering gear that supported the outboard end of the clutch cross shaft? Does the frame have a removable bolt-in trans crossmember (automatic frame) or a welded-in non-removable trans crossmember (manual frame)?