8" rebuild need help. Pinion Spline Count

[Go Pens]

Does any body know the Pinion Spline Count on a stock 65/66 8" rear end. I am not sure if it is 25 or 28. I need to know which to get I have not pulled apart the rear year. I did call Summit racing and they said it should be the 28 spline.

Thanks Brian

[horsehead]

I have to disagree---the stock 8'' is 25 spline---PS-with the 13/16'' pinion shaft size you should have.

[Go Pens]

Here are the two part numbers from Summit. Summit Racing Part Number:

RAT-3024K This is the 25 spline, but under notes it says For use with Auburn carrier or Detroit True Trac.
http://www.summitracing.com/parts/rat-3024k



The other is RAT-3007K is the 28 spline.
http://www.summitracing.com/parts/rat-3007k

Thanks for the help as I am still learning.

[mxg30]

Go Pens,

horsehead is correct.

If we are talking about the PINION GEAR then it is 25 SPLINE.
I believe that the 28 Spline on the Pinion Gear is a typo.

The AXLES on the stock Ford 8 inch are 28 SPLINE.

So these are two different things though they are both a part of the overall rear end of your car and if we are not paying attention as to what we are talking about, then that is where the confusion comes in.

I hope this clears up any confusion.

mxg30

[6T8horse]

X2 on the difference between the PINION and the AXLE spline count

[Go Pens]

I knew the axle where 28 spline. The pinion spline is what I did not know.