Transmission question

[TxCoyote]

Building a 2.2 vintage racer and wondering about gearboxes. I have a 915 but it's stock from a 77s. What is the best way to get a close ratio race prepped box? What ratios? Should I go to a 901 box? Assuming 7:31 diff. Posi I'm sure. Need input.

[Bill Verburg]

Originally Posted by TxCoyote

Building a 2.2 vintage racer and wondering about gearboxes. I have a 915 but it's stock from a 77s. What is the best way to get a close ratio race prepped box? What ratios? Should I go to a 901 box? Assuming 7:31 diff. Posi I'm sure. Need input.

Unless you are very lucky you will need to build or have built what you want

either 901, 911 or 915 can be used as a starter, it's going to be expensive no matter what

here's some info on what was used back in the day

[Gianni at Pelican Parts]

Very valuable and interesting information, thanks for sharing Bill!

[911pcars]

FWIW, I once acquired a 901-5-speed to replace my original 4-speed box. It had a 6:29 rear axle ratio. (4.83:1 vs 4.429). The intermediate ratios (1-5) were unknown, but my stock 2 liter engine was buzzing and probably capable of pulling small tree stumps. I sold it long ago before knowing it's value. My bad.

Sherwood