Yep, I am pretty sure a GTO in 64 was a Nova type rear, leaf spring 42 7/16" center to center measurement The rear will be 1" narrower but should not cause any trouble with tires and install.
Only thing that will be different is the drive shaft length...The drive shaft will need a 3/4" shortening. This should be measured AFTER the rear is installed into the chassis so the exact amount will be correct needed to shorten or find the correct length.
On Behalf Of Jerry Shelton Sent: Sunday, November 01, 2009 7:31 PM To: halftx@googlegroups.com Subject: HALFTX Re: a question on FGF
Bjorn, the rearend will fit, but he will have to watch his backspacing... the rearend is narrower than the Firebird. The yoke and everything should be the same. Do you know if its a 3:55 Posi? If so, its a good rear end, though I would personally have the 4:11 out of the camaro :-D
it is a 3:08 rear end. I am looking for highway ability so not wanting a drag car. Dont want to run down the road turning 3000rpm at highway speed. Thanks for the info Bjorn and everyone else
Oops sorry for the typo on the 64 ot 74 deal. I meant the 1974 GTO was like a NOVA chassis.
The drive shaft from any other GM 10 bolt(7.5 8.2 8.2 BOP) or 12 bolt (chevy or Olds) will need a 3/4" (about) cutting /shortening to make the 10 bolt 8.5 rear end swap fit on the drive line.
The chevy to BOP and vise versa... conversion joint I think is neapco 3310-3 If memory serves me right. Jim
went to see it yesterday. The posi was shot as best I could tell. we had the cover off the unit just to look at it and it looked fine inside. We then took a breaker bar at the drums to test the posi (put breaker bar on each side between drums and eahc guy put pressure in the opisit direction) to see if it would "hold under some pressure it held for a split second and then turned (opposit directions) Put about 40lb of force on the braker. After that I could hold the drum on my side and the other guy could turn his side. That would tell me that the rear is junk right?
On a limited slip both wheels turn in the same direction, but if you hold (lock in place) one drum and then try to turn the other the drum it should eventually break loose I would think. Obviously, the posi has to break loose at some point to allow for cornering. I would think it would need a fair amount of pressure for this to happen. I was able to turn the one side by hand when the other side was held in place
BUY it... GM stock units break at a low pressure to help keep the posi alive longer. TRust me it is still good as long as the spiders are pit free and all the parts are not rusted you can use it. PM me and will take it apart and help you shim it for a bit better performance.