1968 10 bolt rearend carrier swap

[grandpas 68 RS]

I have an origanal 1968 RS that my grandfather bought new, it is a 210 HP 2 barrel carb 327. non positrac reaend. I am in the process of totally restoreing the car for it's 40th birthday. I have rebuilt the engine with correct dubble hump 2.02 heads and four barrel carb and correct manifold. I am keeping the powerglide tranny for now, but my question is about the reaend.  Can I keep the stock ten bolt rearend and swap out the carrier with a positrac carrier to make it a posi reaend? If so what all is needed?

[hotrod68]

Summit and Jeg's sell new Eaton positraction carriers for the Chevy 8.2" 10-bolt. This is a fairly simple swap--just pull out the single-leg carrier and install the stock ring gear on the new carrier, then put it back together. Just be sure it's a 3-Series carrier because your stock 10-bolt is likely geared 3:08 with a 327/210 and a Slip-O-Matic. I'd pull the cover and make sure what the ratio is before I ordered anything! You'll need a cover gasket, 85W90 gear lube, and be sure to go to the Chevy store and get a bottle of GM positraction additive or the clutches will chatter on turns. You'll also need new carrier bearings and some ring gear marking compound to check the mesh of the gears after you put the new carrier in, and a dial indicator to check the backlash, just to be sure. 99 times out of 100 none of the clearances will change enough to be a problem, but you still want to check them. Sounds like a great way to while away a cold winter afternoon in the shop! Good luck!

[rich69rs]

Rear end for stock 327/210 configuration could also be 2.73:1 or special order 2.56:1 ("economy").  Definitely double check the existing ratio.

[grandpas 68 RS]

Thank you for your help. I will pull that rear cover off and and check those gears before I do anything.

[GIBSTER]

So if the gears are 3.08 already could he go with lower ones, But if his gears were in the 2.0's  the carrier would most likely not accept 3.08 or lower is that correct?