hello everyone,

I have a 87 z28 5 speed and unfortunately my rear end has drum brakes. I would love to swap it for disk. I have spent hours on 3rd gen looking for answers. I want to run 18in irocs so a 4th gen rear end won't work after finding out they will stick out. So my only option is a 3rd gen rear end but then there's the 9 bolt and 10 bolt debate. One being stronger and expensive then the other. So my question number 1 is, can I make a 10 bolt strong enough for a LS1 swap with a T56? and question number 2, I know 12 bolts are the way to go, but will I be able to run 18in irocs without it sticking out? if the answer is no, then a 10 bolt 3rd gen disk rear end is my only option to run them beautiful 18in chrome irocs

 

The 10 bolt will hold up fine with the ls1 on the street assuming its in good working order. Beating on it with a sticky tire can potentially cause some problems, but I ran my cam’d 5.3/t56 with my 10 bolt and 4.11’s for years without issue. It even lived behind my lsa blower for about a week...If it wasn’t for me doing a crappy wheel hoppy burnout, causing a tooth to chip off the pinion gear, it probably would still be ok. The key is traction. As long as you don’t beat the crap out it with 6k clutch dumps and sticky tires it will last. However if you plan on frequenting the track and getting some radials or slicks, kiss it goodbye soon rather than later..

If you’re just after disk brakes, I would recommend just leaving the stock rear and doing an ls1 disk conversion. There’s a whole write up on the process below and it’s really not that difficult.

https://www.thirdgen.org/ls1reardisc/

 

thank so much or the advice! I don’t plan of running it on the track but I do plan of running it once in a while and a few burnouts every now and then. I’m given the option of buying a 9 or a 10. Which would you recommend?

I was looking into the disk conversion too! But if I was able to find a disk rear end from a part out for the same price of the conversion Kit it I’ll just be lazy and buy the whole rear end.

 

The rear discs are hot garbo unless you get the 89 to 91 one's with the aluminium calipers. And a 9 bolt with those is $$$$ and RARE.

The 9 bolt is stronger but you pretty much are limited to a single aftermarket 3.70 gear set and the torsen from Australia.... which is good don't get me wrong it's what I run myself. But I already had the 9 bolt.

GD