1976 4 speed numbers
Thread Starter
Cruising
Joined: Oct 2002
Posts: 11
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From: Benton Ill
1976 4 speed numbers
I was trying to find out what kind of 4 speed I have. Thanks to Paul B. I found out that I dont have the original rearend. The numbers I gave for the transmisssion were not correct for type of trans, but it did come with this trans. The other #'s are 1304065903. It also has W.G Div and under that F c 1. There is also what looks like a date stamped upsidedown 7-28-75. If these are not the correct #'s, where should I look? Thanks for all your help.
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Joined: Aug 2000
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From: Massillon,Ohio USA
2020 C3 of the Year Finalist - Unmodified
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St. Jude Donor '08-'09-'10-'11-'12
Re: 1976 4 speed numbers (rjwj1)
From about 1974 and up Corvettes came with Borg Warner transmissions, other than some '78's that came with Saginaws? Even though they were Borg-Warners, they still used the M-20 or 21 designations for close OR wide ratios up until '79?. I don't know of any way to tell the difference externally for the identity of a close or wide ratio BW. I do know just by driving them in the difference. If your trans rpms drop 250-350 rpms between shifts, then you have a "close ratio". Wide ratio trans the rpms are more "spread out" and will drop 500-650 rpms between shifts. Having a '68 with an M-21 and an '80 with a wide ratio BW, you can easily tell the difference just by driving the two different cars.
