I recently purchased a 10 bolt to replace my bent 9 bolt (had another thread here showing the negative camber). The 10 bolt had bee previously on the same ear (85) camaro. it came with trque arm and drive shaft and is complete disc to disc. my car has already been set up for rear disc brakes. Anyway, im wondering if this is a bolt in matter or if the swap might require a different drive shaft length or T. arm, etc. ? I wouldnt think so, but before i get under there, wondering if there could be any issues. 700 R 4 tranny...Mark

 

No issues, direct swap. Why switching to 10 bolt, 9 bolt broke?

 

aye... direct swap

a thing to look into tho, is if your fuel pump is old or if your planning on a motor build up sometime down the road, might as well replace the pump while u have the rear down and have access to the gas tank

 

yeah, the 9 bolt rear end was bent or something, there was a lot of negative camber on the tires. i had a recent post witha pic of how bad it was..."negative camber issue" so i figured the solution was just to replace it. got a good deal on this and luckily i was able to pick it up myself without a lot of hassle. generally, if you know, what quality differences are there between 9 and 10 bolt rears. I do know this has a posi and gears go from something like 3.29 to the new one with 3.45. these ratios are off the top of my head and may not be accurate at the last decimal point...
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I just had a crate engine put in, its carbed. i am also replaceing the shocks and springs etc. while the rear end is out.

 

10 bolts are a 7.5 or 7.625 inch ring gear. yours came out of a 85 you say, so its probly a 7.5inch. i think 87 they upgraded to the 7.625 inch.. not much of a difference tho.

9 bolts are a 7.75 inch gear.. its abit stronger than the 10 bolt.

9 bolt gear ratios are 2.77, 3.08, 3.27, 3.45, 3.70
10 bolts are 2.73, 3.23, 3.42, 3.73, etc

9 bolts are a cone type posi.. which uses friction from the cones to engage the posi action. 10bolts i do believe are just a clutch type posi. you usually have to had a posi additive to 10 bolts while 9 bolts you dont, as posi additives are friction modifiers, and when put into a 9 bolt, the cones lose friction and slip... so now u have a one wheel peel. Although some ppl have had success with adding a additive to the 9 bolts.

10 bolts have a LOT bigger aftermarket.. more parts like axles, gears, posi's, and etc. so thats a big bonus if you need to strengthen the rear or if something breaks and u need to replace it.

thats pretty much all i can think off when it comes down to the 2 rears.

 

hey! Thanks alot! Good info here. I had heard that it was hard to get parts for the niners. im not doing any drag racing or anything, so it should be fine.