I've located a nine bolt positrac rear with 3.27 gears for $140, and from what I've come to understand, these things are pretty sought after. But as with all positrac they wear down. Would it be worth it to buy the rear and replace cones if needed, or do the posi units generally need more than that?

 

Honestly, I'd stick with a 10 bolt rear. 9 bolts are said to be a bit stronger than the 10 bolt rears, but they're not worth the trouble in my opinion since replacement parts are impossible to get. You can buy bearings and seals for them all day long, but there's no such thing as getting a new posi unit for one, and the only aftermarket gearset available is 3.70. You can't buy new replacement cones for the posi unit either. I'm sure you might have seen the tech article here about machining the cones to fix the posi unit, but this is only doable if the cones haven't worn down to the point to where they're bottoming out. And even if you do machine the cones, it's only a matter of time before they wear out again, and probably for good the next time they wear down. What's nice about the 10 bolts is there's more aftermarket replacement and upgrade parts available than you can shake a stick at! In addition to that, the 10 bolt rear actually holds up quite well if you drive sensibly and don't beat the holy snot out of it! My buddy is still running a 10 bolt in his 95 formula which has an AFR-headed, LT4 hot-cammed 383 in it, and it's holding up just fine. If you decide to go ahead and buy it, who am I to stop you, but realize you'll be dealing with a rear that's obsolete as far as parts suppliers are concerned!

 

9bolt parts can be bought from aussy land, they still use that rearend. It does take work to find em but they can be had..

 

Yeah you can find stuff for them in the land down under, but you're gonna pay big bucks for the parts and the shipping costs! In fact, it's said that the new GTO's used the 9 bolt rear, but some people say it's the same as the 3rd gen 9 bolts internally, while other guys say it's completely different, so who knows for sure.

 

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