[JC455]

Well, it looks like Jeff Smith (former Hot Rod Editor and current Chevy Hi Perf. Mag Editor) let the cat of the bag on first gen F body ten bolts, so I might as well share the info with the Pontiac Community.
First off, I'd like to state that this is something I've been sharing with other 67-69 Firebird owners for years, and believe me it works!
If you take the rear end from a 2nd gen Nova ( or Ventura, Omega, or Apollo) from '72-'74 (CHP states 75, but I've never tried a 75 rear) that is and 8.5" unit, it'll fit right into where the WEAK 8.2" unit was. I've always taughted the 8.5's strength (a 12 bolt is 8.875" on the ring- a big .1875" larger per side than an 8.5" ten bolt) and Pontiac must have thought they were stout enough- the SD455 cars got 'em.
Anyways, you can use the many available limited slip units (or the factory T/A units) and find all types of gears for next to nothing. This is really evident when you price a 9" or 12 bolt for a first gen car(You also get the benefit of multi-leaf rear suspension, which can be swapped into 67 cars).
How about gears?? There's only two carriers- 2.42/2.56 and 2.73-up. That's right, no 2,3,4 series carriers to mess with. If you've ever priced a 12 bolt L/S unit, you'll know what I mean when I say cheaper and less hassles.
Want a killer street set up for cheap? Go to Pick-a-part (or whatever you have) and score a housing. Cruise around in the rear of the 2nd gen cars and score on a ring gear you like. Then go find a Trans Am and snag the L/S unit out of it.
Call Summit for a rebuild kit and take it to a gear guy to have all these pieces assembled.
You've just built an 8.5" that'll handle a 455 (in the curves, no less!) for under $500.00
While I realize this is not a high dollar drag-race-it-til-it-blows rear end, it'll be perfect for the streets and for autocrossing.

Now, have I ever told you about how easy it is to install rear disc brakes?


------------------
John

[JC455]

Well, it looks like Jeff Smith (former Hot Rod Editor and current Chevy Hi Perf. Mag Editor) let the cat of the bag on first gen F body ten bolts, so I might as well share the info with the Pontiac Community.
First off, I'd like to state that this is something I've been sharing with other 67-69 Firebird owners for years, and believe me it works!
If you take the rear end from a 2nd gen Nova ( or Ventura, Omega, or Apollo) from '72-'74 (CHP states 75, but I've never tried a 75 rear) that is and 8.5" unit, it'll fit right into where the WEAK 8.2" unit was. I've always taughted the 8.5's strength (a 12 bolt is 8.875" on the ring- a big .1875" larger per side than an 8.5" ten bolt) and Pontiac must have thought they were stout enough- the SD455 cars got 'em.
Anyways, you can use the many available limited slip units (or the factory T/A units) and find all types of gears for next to nothing. This is really evident when you price a 9" or 12 bolt for a first gen car(You also get the benefit of multi-leaf rear suspension, which can be swapped into 67 cars).
How about gears?? There's only two carriers- 2.42/2.56 and 2.73-up. That's right, no 2,3,4 series carriers to mess with. If you've ever priced a 12 bolt L/S unit, you'll know what I mean when I say cheaper and less hassles.
Want a killer street set up for cheap? Go to Pick-a-part (or whatever you have) and score a housing. Cruise around in the rear of the 2nd gen cars and score on a ring gear you like. Then go find a Trans Am and snag the L/S unit out of it.
Call Summit for a rebuild kit and take it to a gear guy to have all these pieces assembled.
You've just built an 8.5" that'll handle a 455 (in the curves, no less!) for under $500.00
While I realize this is not a high dollar drag-race-it-til-it-blows rear end, it'll be perfect for the streets and for autocrossing.

Now, have I ever told you about how easy it is to install rear disc brakes?


------------------
John