JarHead1st

Hello.....Finally gonna get my wife to shut up by rebuilding my lime green 71 vert. I don't know sh*t but I'm learning fast! Didn't want to post until I took some photos but here goes - Stripping down the car it has the peg leg 10bolt 8.5 rear, want to move to a posi and disc brakes. Should I move to a 8.6 buy a complete done piece or try to redo the one I have(new gears, better axles etc) or buy a done 8.5 and convert to disc. I don't have the skills to do the gear set(lash). Also welcome any advice on ratios(thinking 3:7something to make up for the extra weight), I am dropping in a drivetrain from a 2010 ss camaro, LS3/six speed (480hp) has a 3:45 gear set. My car is heavier don't know what my tire size will be and I do not intend to race just want a fun dependable street car that I intend to drive.......alot cause it's fun! Thanks

70cutty

I would rebuild the rear end you have. It's a 10 bolt with bolt in axles. If built right it can be as strong as 12 bolt. With the LS setup you are gonna run you could probably step it up to more aggressive gear like 4:10 cause it's a 6 speed. You can PM monzaz (Jim) great guy, very knowledgable and has helped many(including me) with good quality rear end problems and parts. He can point you in the right direction.

76olds

X2 Monzaz ( Jim) purchased all my 10 bolt 8.5 rear parts from him, Great guy with awesome customer service .

507OLDS

Build the existing rear that you have. It will be fine behind that drivetrain. 3:73's,3:90's,or 4:10's would work great with that combo.

billmerbach

Ahhhhhh a newer chebby engine in an olds seriously tho sounds awesome but do as they say I haven't been steered wrong yet by these guys

monzaz

oNLY DIFFERENCE FROM A 8.5 OR AN 8.6 IS THE CARRIER BEARING DIAMETER and spider gear design. 8.6 Ring gear will be the same as any 10 bolt 8.5...Same deal as the 7.5 to the 7.6 same rear just subtle differences in the spider gear design and they increase the axle spline count from 26 to 28 ...
el;
Your 10 bolt 8.5 71 72 rear will hold on the street with stock axles. If you are planing to hit the track frequently, upgrade to the Moser 30 spline set-up and 30 spline eaton or true trac posi unit You will be fine for a high 10 sec run



Take care, Jim

JarHead1st

Thanks Jim. How much would the upgrade cost me for you to do? Would it be cheaper to get someone locally? I want to go stronger while I have the car apart and add disc brakes, gonna have to do some research this weekend when I can search through all the info on this and other sites. Gotta be some "favorite" donor brakes I can pull from the junkyard. Thanks again