34 pinion spline question
 

I'm putting a Mitchell overdrive in my 34 coupe. It has a 4.11 rear end. When the overdrive arrived it came with a 6-10 spline coupler. My pinion is a six spline so I needed the 6-6 spline coupler. Is six spline correct for a 34\v-8? Or has someone changed it? Don't know what years used six and which ones used ten. I have searched several sites and have mixed results. Thanks, Steve

Re: 34 pinion spline question
 

It would have been 10 spline originally
Question ,do you have to cut the floor plan to fit the mitchel in?
Lawrie

Re: 34 pinion spline question
 

Hopefully not! According to their website it requires no body modifications. I'll know when I get the correct coupler. I didn't think the later 6 spline pinion would fit the 33/34 housing with the small pinion bearings? Is it possible to swap them? Steve

Re: 34 pinion spline question
 

I think that there are some made with 6-spline for the late 32 thru 34 type axle but your car may have had the rear axle replaced with a later type too. Some folks do this to get the beefier characteristics of the later axles. There are several threads on this forum that are about rear axle ID. Some contain an article that was reprinted from Hot Rod Magazine. In fact one of them was pretty recent if you do a search. The 6-spline pinions came along in 1938 or so and the retrofit works for 1935 through 1948 for that.

Mitchel should be able to do a 6-spline shaft since there stuff is all modification anyway.