I currently have a 10 bolt in my iroc. I bought a trans am with a 9 bolt rear with disc brakes and a tpi engine with the intention of swapping those to the camaro. I've decided I don't want to bother swapping engines. Now I'm trying to decide if the 9 bolt is worth it. I've heard they are hard to get parts for and that they aren't much stronger. Somebody wants to buy the trans am whether I swap rears or not. So my question is should I swap them or save my money for a newer bolt in kit?

 

It seems to me that the 9-bolt was stronger than the 7.5 w/ 26-spline axles, and it was the 9-bolt that GM installed behind the '87 350, but by '91, the 7.625" had 28-spline axles, and was being used behind the 350, which had gained some power by then. Further, the 7.625" kept getting used for the 4th gen, when GM had every chance to bring back the 9-bolt, or give us something else. Further, the 7.625" stayed in the car when the LS1 arrived.
So is the 9-bolt really stronger than the 7.625" ?
GM dropping the 9-bolt may not have been about the strength only, and GM not giving us the Dana 44, or GM's own 8.5", raises other questions, but some of the LS crowd are getting the 7.625" into the 11s in the quarter mile, at full weight.

 

Thanks for the reply. I'm not building a track car, and I don't do many burnouts and stuff(mostly because my 200k+ mile engine didn't have many ponies left). What is in the car now survived my teenage years with just as many miles as the engine so I'll probably be okay with the 10 bolt. If I ever get to working on the engine I'm only planning to go around 350hp max.

I think I'll sell the trans am to the kid, he wants a project car for jvs. Plus the city won't stop harassing me about it. Every couple of months a cop shows up, I show them my registration, proof of insurance, start it up for them, I hardly drive it and it fires right up every time. And I always ask why they keep bothering me since my registration is good for a year, and my insurance is good for a year, and they've seen it run several times. And they just say "see you in a few weeks".

 

I'll take the bolt-in 9-bolt axles over the C-clip 10-bolt axles any day.

9-bolt parts aren't hard to get. Just can't get them in any parts store you walk in to. Australia is still using the 9-bolt center section, so the parts can still be found.

 

C-clips are not the nightmare that everyone exaggerates them to be. If you're running a 7.5 / 7.625, then the gears are weaker than the 28-spline axles, so no worries about losing half an axle.
If you do have 26-spline, then the conversion to 28 spline is easier than trying to do your own c-clip eliminator kit under your shade-tree. I helped a buddy do his, we got it back on the road, but we agreed it's easier to swap in a Ford 9".

 

If your running the stock TBI engine than pretty much anything will work. You wont even come close to taxing either rear with that engine. Really its a matter of what gears are in each. If the 9-bolt looks good inside, and has good gears and a 3-series carrier, its worth rebuilding and either using it, or selling it. If it has 2.77's in it than its not worth much as that carrier can only accept the 2.77's and no other numerical ratio gear set.

 

ive busted both nine and ten bolt... just something to think about....