Early Style 9" Or Use Pontiac 8.2?
 

Ok, so here is the deal. I found a really good price on a 9" ford rear out of an f100, its complete drum to drum. The rear is from 1959 though, will this rear be better then the 1968 pontiac 8.2?

Pontiac 8.2 has already been powdercoated, new auburn posi, new gears, new bearings, stock axels, 12" rear discs.

The 9" from 59'
Stock drum to drum, I would have the axles cut to correct length, Gm ends, disc brakes...etc etc

WHICH IS A BETTER PLATFORM?

Thanks guys

If I'm not mistaken, they'll both be 28-spline axles, however the F-100 will obviously have a different wheel pattern, so plan on new axles or welding and redrilling the Ford axles for the GM 5x4.75 pattern. I'm pretty sure that that 9" will use the 80mm "big" bearing housing ends with the 2.375 x 3.500 flange pattern, 1/2" retainer bolts and 2.36" brake offset dimension, however I've seen some variations with respect to the brake/axle offset depending on the application, so that would be good to confirm one way or the other.

The 9" will hands down be the stronger of the two with respect to the R&P, however it will also require a fair amount of money to get it to where your BOP already is. What's the projected HP/torque for this thing and how do you intend to use it if you don't mind me asking?

Tobin
KORE3

Well, I was going to swap out the axles anyways, track lock, new gears, Gm ends. He is only asking $75 complete

I have an Ls1 5.7, forged bottom end, profiler heads 300 cfm (215cc), fast 90 intake, 232/236 cam, it has some nice parts to make the LS1 really open up. Should be around 500 hp......Will be a Street car mostly, occasional autocross, track days.

That's cheap...but may not save you much if you end up replacing or modifying everything. Given your engine build, you'll want alloy 31-spline axles minimum, however going 35-spline will require an aftermarket diff housing. I'm not a big fan of the Trac-Lock myself, 2 or 4-spider, however a Detroit True-Trac could hold up with ~450-ish RWHP and shouldn't have the wear issues associated with a clutch type limited slip or the tendency to break the carrier like the True-Trac's.

It's certainly a good enough deal that you'll come out okay even if you don't use it and just sell it down the road, otherwise I'd probably look for a later 1979-1986 F-150 or E-150 9" with 31-spline axles, SET20 axle bearings and the larger 3.062" carrier bearings. These were commonly supplied with 3.50 gears and 4-spider Trac-locks...sometimes pre-broken for your convenience.

Tobin
KORE3

Early 9 inch or Pontiac 8.2 ?
 

I wouldn`t use either .I would look for a GM 8.5 10 bolt out of 1973-8 Nova or one X body cousins.Because they are just as Chevy 12 bolt.They bolt right in; and you can transfer your rear disc brakes over to it. Keep or sell the 8.2 for a "stocker" .to defray your cost. Good luck to you.