I'm planning on replacing the Olds 403 in my 79 TA with a Pontiac 455. The goal is around 600 hp and 600+ lb ft on the block and maybe a nitrous kit if I need even more speed. What kind of power can the factory rear end be built up to hold? The rebuild plans include welding the axle tubes, new axles, new gears, a new Eaton or Auburn posi unit, and a performance diff cover. Or am I just wasting my time on rebuilding the axle instead of just going straight to a Ford 9"?

I'm planning on replacing the Olds 403 in my 79 TA with a Pontiac 455. The goal is around 600 hp and 600+ lb ft on the block and maybe a nitrous kit if I need even more speed. What kind of power can the factory rear end be built up to hold? The rebuild plans include welding the axle tubes, new axles, new gears, a new Eaton or Auburn posi unit, and a performance diff cover. Or am I just wasting my time on rebuilding the axle instead of just going straight to a Ford 9"?

There are folks running into the 9s on GM 10 Bolt rears i beleive.
600hp you better have some good stuff in the motor :P
Mike

If the budget allows, don't even mess with the 10-bolt. I have a 10-bolt in mine with good parts, but I bought it used and in great shape at a cheap price.

If you want to stick with the 10-bolt, you'll need to:

square axle tubes and weld to housing
install C-clip eliminators
install Moser axles (the more splines the better) or equivalent
install a cover/girdle (like from T/A Performance)
install the beefiest differential you can find

http://kurtspontiac.homestead.com/files/bbaker.jpg

Seen cars in the 9's also with 10 bolts, usually a spool and aftermarket axles. The ring and pinion are almost as strong as a 12 bolt.Your proposed mods wil be pretty strong, an Eaton 4 spring 30 spline posi and good axles should get you pretty close.

You can run high 10s with stock axles and posis. The Parkers in Dallas did it for years. My car currently is doing it, except I have an Eaton 28 spline posi.But it may be life on the edge.Piece of mine would definitely be C clip eliminators and good axles.

Thanks for the input and the knowledge that I can get into the low 10's and maybe even the 9's on the 10 bolt. Now I just need to price it all out and see how it compares to a quality 9 inch from Moser or Strange.

How do I know if i have a 8.5" or 8.2"? Ive always figured I had the 8.5 and was planning on keeping the it, I might go ahead and throw some good axles and c-clip eliminators while I'm at it. Anybody know where to get rearend components?

Project: Black Hawk
See the saga unfold here: My 455 Firebird
2001 Camaro Z28 6-speed: [email protected] stock cam, stock heads, stock rear, stock clutch

[This message was edited by Firebird455 on August 15, 2003 at 11:33 AM.]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Firebird455:
How do I know if i have a 8.5" or 8.2"? Ive always figured I had the 8.5 and was planning on keeping the it, I might go ahead and throw some good axles and c-clip eliminators while I'm at it. Anybody know where to get rearend components?

_Project: Black Hawk_
See the saga unfold here: My 455 Firebird
2001 Camaro Z28 6-speed: [email protected] stock cam, stock heads, stock rear, stock clutch

[This message was edited by Firebird455 on August 15, 2003 at 11:33 AM.]<HR></BLOCKQUOTE>

If the rear in your 'bird is original, it's an 8.5"

http://kurtspontiac.homestead.com/files/bbaker.jpg

even if it was a base model firebird with a crappy 301 and 2 barrel? http://forums.performanceyears.com/g...on_biggrin.gif

Project: Black Hawk
See the saga unfold here: My 455 Firebird
2001 Camaro Z28 6-speed: [email protected] stock cam, stock heads, stock rear, stock clutch

Pontiac stopped using the 8.2" rear sometime by 1972 (I think). Everything after that was 8.5". There was a 8.5" BOP, and a corporate. Yours is most likely like mine, a corporate.

http://kurtspontiac.homestead.com/files/bbaker.jpg