6
6T3Vette
Guest
Hopefully you guys can bail me out. I recently bought a 3.55 Posi out of a '79 Vette with an automatic transmission off of ebay. My intent is to swap it out with the 4.11 Posi that is currently in my '63. While I love the take-off power, I'd like to have something in her that is more gas friendly.
Here's the problem. The companion flange yoke on my '63 is 3 1/2" and the flange on the 3.55 is 4 1/2". I thought I could simply put my flange on the 3.55, however, after pulling both flanges off I discovered that my 3 1/2" has 17 splines and the 4 1/2" has 30. Is there a 3 1/2" flange that was made with 30 splines on it or is there some kind of conversion or work-around I should be looking for? Someone also told me I may be able to use the pinion out of my 4.11 on the 3.55. I thought that sounded hokie. Doesn't the pinion and ring gear need to be a matched set?
Thanks,
Terry
Here's the problem. The companion flange yoke on my '63 is 3 1/2" and the flange on the 3.55 is 4 1/2". I thought I could simply put my flange on the 3.55, however, after pulling both flanges off I discovered that my 3 1/2" has 17 splines and the 4 1/2" has 30. Is there a 3 1/2" flange that was made with 30 splines on it or is there some kind of conversion or work-around I should be looking for? Someone also told me I may be able to use the pinion out of my 4.11 on the 3.55. I thought that sounded hokie. Doesn't the pinion and ring gear need to be a matched set?
Thanks,
Terry