new speedo gear

[Teds89IROC]

The iroc came stock with 2.77's, I swapped rears to a 3.42 and now that I'm filling out the voucher for collectors registration (no emissions testing :-D) I want my speedo to be correct so that limited 3k miles/year doesn't creep up on me. Is the speedo gear inside the tranny interchangeble between 3rd and 4th gen auto transmissions? Has anyone gone to a dealer and gotten this gear?

~Ted

[camaro2you]

im in the same boat as you.

[foff667]

http://www.transmissioncenter.net/speedometer_calibration_______va.htm

[Teds89IROC]

Thanks for the site, but is a 275/40/17 tire 27" tall? and being that the 3.42 is out of a 4th gen, how do I know the tooth drive gear in my 89 is 17? Unless I go to the dealer and buy a speedo gear for my 89 to accomodate a 3.45 rear. Some stock cars came with the 3.45 9 bolt rear and it would be pretty damn close to 3.42.

~Ted

[V]

3.42 gears were available in the 3rd gens. many of the V6 cars got that option. I had an 85 berlinettea with the 2.8, automatic 700r4, and a 3.42 10 bolt rear.

[Tru2Chevy]

Yea, my old '85 2.8 had 3.42s as well....

- Justin

[Teds89IROC]

oh ok, then **** that site, I'll just go to the dealer

~Ted