Is the Posi worth the budget hit for my Challenge car?

curtis73 wrote:

Gasoline wrote: 8.5"? or 7.5"? Pretty sure Monte Carlo SS's got both.

Nope, Montes got the 7.5" The SS got 7.625 which is the same case with a bigger ring gear/carrier. Its no stronger since the main failure point is the bearing caps.

They put a bazillion of those 8.5" rears under everything, I would have thought the SS would have got one, but you are right small 7.5x rear end with 26 spline axles.

G Body 8.5" are big $$$ bucks. The ZR2 S10/Blazer might be a canidate for a 8.5" rearend. 5X4.75" pattern. Might be a tad too wide?, but probably has a good gear choice, possible posi, and the late ones got disc brakes. Just a thought.

AI will add another vote for the Explorer rear. Explorer axles are also bigger 31 spline compared to the GM 28 spline.....if you are into breaking axles.

WE were lemons racing our 3.73 and then later 3.41 Monte carlo SS rear. We NEVER had a problem with it. It hooked up just fine.

The car had a 350 GM goodwrench crate motor that we ran with a TBI (Tuned with my wideband / different injectors / and pressures).

We also ran this combination with a TH350 trans and then a saginaw 4 speed. The 4 speed was much funner.

Again, we never had an issue with the rearend.

wae wrote: Make 1,000 pounds' worth of El Camino disappear?

I thought your favorite suggestion was ditching the original engine configuration completely and putting something FWD in place of the rear end?

Hmm. Is it too late to vote "BOTH"?