Will be swapping out a transmission on an 85 Z28 305TPI. Need to find our what rear end he has. This is the number I got off his diff. 22522678. Reason I need this so when the time comes I now to swap out the speedo. Thanks.

 

There is a good chance the speedo drive gear on the tranny output shaft will be the same on both trannys. Pull out the driven gear and look - if they're the same color, they're the same # of teeth. Then, just put back in the driven gear that is in the car now (the driven gears are color coded as well).

A better way to determine the gear is to find the 3-charactor code on the front of the passenger side axle tube (will be something like "5KG"). A Haynes manual will have a decoder section. The best way to determine the ratio is to pull the back cover off and read the teeth #s stamped directly on the ring and pinion gears. Then, get the calculator out and divide the ring teeth by the pinion teeth to get the ratio. This is "best" because the gears could have been changed by a previous owner, and this is a good time to change the gear lube (which is often neglected).

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.73 unlimited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, TBD heads, exhaust, paint, etc.).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

[This message has been edited by five7kid (edited December 21, 2000).]

 

five7kid, thanks for the info.

 

double post

[This message has been edited by 86z/92rs (edited December 21, 2000).]