The 8.5-inch 10-bolt axle required to bolt directly into a '67-'69 Camaro or Firebird can
`The first-generation Camaro has achieved rock-star status at this point. We saw something like 15 of them in various displays at the '05 SEMA show in Vegas. But if the mail and the people we encounter on the road are any indication, there are still plenty of these cars in the hands of grassroots enthusiasts. Even if you weren't fortunate enough to secure one before the Barrett-Jackson boom, there are still loads of formerly junk '67-'69 Camaros out there to resurrect, so long as you're willing to do a whole lotta welding.
That said, there's still the matter of actually building the car to do what you intended in the first place: go fast. But if you find yourself getting annoyed at the prices complete cars are fetching, wait til you see the coin needed to score key parts and pieces. For example, any early F-car worth its salt ought to have a 12-bolt, right? Good luck finding an original, and when you do, it'll likely take north of $500 just to get a core that still needs to be rebuilt. Sticking with the stock 10-bolt isn't much of an alternative. It's a wimpy 8.2-inch unit, and really isn't worth investing in since you're going to need gears, a limited slip, probably new axles, and so on, and you'll still have to fret about grenading it every time you launch. Of course, the aftermarket can offer you a choice of a brand-new bulletproof 12-bolt, 9-inch, or Dana 60 ready to bolt in, but it'll take in the neighborhood of two Gs to get one. If you can afford it, the new heavy-hitters are great, but if not, we have an alternative.
The 8.5-inch 10-bolt axle hadn't reached production during the era of the first-gen Camaro but soon after became a staple for GM cars. This stronger 10-bolt was intended as a "corporate" axle to be used across GM lines, and it had to be fairly strong as the 12-bolt was going away. Chances are you've abused one of these axles before and probably didn't even realize it, since it was used in pretty much every '71-'81 F-car, as well as '73-'77 A-body cars, '71-'76 B-bodies, heavy-duty '77-'96 B-bodies, '84-'87 Turbo Buicks, and countless scores of 12-ton GM trucks among others. But the application that matters most to our story is the '71-'74 Nova and other X-body clones. This is the one that bolts right into a '67-'69 F-car, and this is the way we're going to build a stout rearend for a modest investment.
As you might guess from the long list of applications, parts for the 8.5-inch 10-bolt are plentiful and carry relatively painless price tags. There are also several ways to go about building this rear, depending on your needs and budget. We're focusing on an upgraded 10-bolt using a brand-new differential, gears, and 30-spline axles--the same as those used in factory 12-bolts, but check the sidebar for more budget-oriented alternatives.