View Full Version : '27 T rearend question

06-21-2008, 08:42 PM
In case of "Luck of the draw" that I don't get a posi rear end for my 1927 T roadster, what are the specs I need to know about the rearend while haunting eBay for a posi unit?

I found this: GM 7.5 10 BOLT 28 SPLINE POSI UNIT 3 SERIES

Will this work? If not, what ring gear size and spline do I need?

Thank you in advance for any help.


06-23-2008, 07:48 AM
This is the same rear end that is used in s10, camaro and firebird is a good choise for a tbucket. I dont know what gear set up is it can be determined by turning the pinion and counting the turns of the axel :cool: :) Smokey

06-23-2008, 08:21 AM
You want about 52" backing plate to packing plate.

06-23-2008, 08:49 AM
Sorry, didn't write my message clearly. I just wanted to know what the ring gear size is in the 10-bolt rearend I'm getting (from Spirit) is and if the axles are 28 spline? Or, easier, what year S10 (year range 1989-1993?) did it come off of?

I just bought a posi unit off of eBay and was hoping I bought the right one.

Thank you for your help.

06-23-2008, 11:34 AM
the rearend comes out of a S-10 blazer 4x4....94 and up they used the same rearend....the best thing is to wait until you have the rearend so you make sure you get the right thing....

06-25-2008, 12:03 AM
I was wondering this also, how often would you say the Spirit kit comes with a
posi unit?

Can you request one or is it the luck of the draw?:confused: :)

27 roadster
06-25-2008, 05:00 PM
when you say backing plate you mean the brake shoe backing plate and not the the outboard end of the axel where the wheel bolts on at? thanks for clearing this up.

06-26-2008, 09:28 AM
To get a posi it is a luck of the draw...backing plate is the plate is the inner most part....not where the wheels bolt on.