12 Bolt Rear End Advice

[rlehto]

I just picked up a 71 El Camino 12 Bolt code read CFC which should be 3.31 posi. I noticed the wheels didn't turn in the same direction thought it might be due to worn posi unit but I opened it up and it had 2.73 and was aa open rear end. I paid $500 so not to bad the guy thought it was open I don't know why someone would take out the posi and 3.31 for open 2.73?

Anyways few questions:

1. Before I took out the carrier the pinion and ring would not spin do I need to add some sort shims? The teeth look great they just seemed to be bound up when fully installed. I'm new to rear end stuff.

2. While I have everything out should I upgrade to a posi and a higher gear like 3.31 or 3.73. My application will have a LS1 with T-56 daily driver. Pretty basic maybe down the road add a twin turbo setup.

3. If yes to upgrading to the posi and gears wheres the best place to buy them? Also what else should I replace while I have it apart?

Thanks for the help.

[MrQuick]

1. Before I took out the carrier the pinion and ring would not spin do I need to add some sort shims? The teeth look great they just seemed to be bound up when fully installed. I'm new to rear end stuff.

When you put it together you will have to adjust lash. It might have been a bearing hung up or something.

2. While I have everything out should I upgrade to a posi and a higher gear like 3.31 or 3.73. My application will have a LS1 with T-56 daily driver. Pretty basic maybe down the road add a twin turbo setup.

4:11's would be perfect but your tire size would help with selection.

3. If yes to upgrading to the posi and gears wheres the best place to buy them? Also what else should I replace while I have it apart?

Thanks for the help

https://www.pro-touring.com/forum/member.php?u=6990 PM this guys, he can help you with all you need.

Don't forget Frank at Prodigy customs too.
Also congradulations on the rear. Thats a great price.

[rlehto]

Thanks MrQuick

Tire size not sure I would guess 17" 18" wheels with 315/25/R17 or 18 I think thats the biggest I can fit right? Its a stock 70 Chevelle

[rlehto]

So 4.11 would be better for power and daily driving kind of driving?

[big gear head]

Sounds like someone just stuck this thing together to sell it. I can help you with the parts. Let m eknow what you are interested in and I'll help you get the right stuff.