Spine #

[parrisc19844x4_468]

Does anyone know what # spine would be on my 1984 K10. It has the stock 10 bolt 8.5 Corp rear end. I have a chance to pick up new new ring and pinion / install kit. I know I could pull the shift off and look, but I am meeting up with the guy today.

[parrisc19844x4_468]

whops. wrong place ..plz move

[parrisc19844x4_468]

spine #
Does anyone know what # spine would be on my 1984 K10. It has the stock 10 bolt 8.5 Corp rear end. I have a chance to pick up new new ring and pinion / install kit. I know I could pull the shift off and look, but I am meeting up with the guy today.

[Heavy87Chevy]

I just rebuilt my rear diff a couple weeks ago & was looking into this stuff. I believe if its a 'standard' (non-locking) diff in the rear, it will be 28 spline & if its posi it should be 30 spline, you can find out if its 'standard' by looking at the RPO codes. I would expect it to be a standard diff given that its a 1/2 ton.

GQ1 REAR AXLE - STANDARD (NON-POSI)
G80 REAR AXLE - LOCKING TYPE

[BIG V]

actually in 1989-1991 ish only in the suburban and the blazers came with 30 spline axles your truck will have 28 spline axles, it doesn't matter if it has a posi or not. go to the loacal pick in pull if you want to upgrade the axles look for the blazers or burbs

[Heavy87Chevy]

Originally Posted by BIG V

actually in 1989-1991 ish only in the suburban and the blazers came with 30 spline axles your truck will have 28 spline axles, it doesn't matter if it has a posi or not. go to the loacal pick in pull if you want to upgrade the axles look for the blazers or burbs

You sure? my 87 1/2 ton had 30 splines. & it was a stock non posi rear.

[parrisc19844x4_468]

Thanks guys, that is why this forum is great.

I bought the set yesterday complete with the installation kit for $140. Gears have never been installed.

Got home and couldn't wait so i opened up the rear end, pulled the axles and front yoke off, pulled the gears. It is a 28 spline. What was supressing , well somewhat, was that the gears are like in the low 2's believe it or not. I need to get a new carrier for the 373's.

[ont_guy_38]

from 2.73 up use the same carrier so unless you have the 2.56 i think they are then you are good to go

[BIG V]

Originally Posted by Heavy87Chevy

You sure? my 87 1/2 ton had 30 splines. & it was a stock non posi rear.

I work at a differental shop have been for 13 years 99.9% positive American Axle Manufacture did not make a 30 spline untill 1988. Some of the 88 square body blazers and suburbans have 28 spline axles some have 30 spline axles. Its safer to say its from 89 on our square body's. However the 88 and up pickups all have 30 spline axles.