IROC-Z Driver

I'm putting an LS1 into to my '86 Iroc, and this is my first time doing this. Is the stock rear end going to be able to handle that motor, or should I get something else? I apologize if something like this was already posted, but internet in Iraq sucks.

arrowcamaro

iTrader: (2)

LS1's also come with 10 bolts.

DJP87Z28

Basically the same 10-bolt was used on all factory stock LSI 4th Gen Z-28s.

IROC-Z Driver

Thanks guys. Thats great. I'm trying to get this all worked out before I get home in a month. Just wanna drop it in before fall hits.

Stephen

iTrader: (12)

Yes, LS1s came stock with 10-bolts....But what the problems are, is the 3rd gen differential is a bit weaker. As well as, the early 3rd gen 10-bolts had 26-spline axles. The 28-spline axles will be a bit stronger.

That being said, I would look into when things changed & see what you have in your car.

Just toss in a 4th gen LS1 rearend & you'll get the stronger parts, plus bigger disc brakes. It's a win-win situation, with zero downsides.

Spiers

iTrader: (7)

The newer 10 bolts suck too.

Stephen

iTrader: (12)

Not enough that GM wouldn't put a warranty on them.....It is the T5s that were the weaker point in 3rd gens.

kmo1188

iTrader: (1)

I cant help you much with your question. I just want to say thank you for your service. Be careful man.

IROC-Z Driver

So if I were to swap a 4th gen into the car, would I have to change anything else out? or would it bolt right in? Thanks for the thanks, of course I'm careful, I have a great dog, and a fantastic car to work on... life doent get much better than that. One more question though, would it be worth it to go ahead and just drop something new in? like a new Moser rear end? I plan on putting a new cam and some other work into the LS1. Thanks guys.

DJP87Z28

It will work, just remenber it is 3" wider overall. you may replace minor items like the brake line, parking brake cables & brake parts.

Ah, a Moser rear. A fine rear axle if you have a extra $2500 + laying around.

arrowcamaro

iTrader: (2)

Depends on a couple things. 6sp, or auto? Hittin the drag strip with sticky tires?

If its an auto and not seeing any strip time the 10-bolt should hold up. If you're planning on side stepping the clutch on sticky tires dont plan on the 10 bolt to last long.

IROC-Z Driver

Yea about that $2500.... unless anyone is willing to make a donation, looks like I'm sticking with looking into a 4th Gen. Thanks guys

Spiers

iTrader: (7)

If you look you may find a used 9inch or 12 bolt for ~$1500-2000. But for $200 or less, you can put a 4th gen 10 bolt in, and see how long it lasts. If it breaks then it's cheap to replace. And like arrowcamaro said, it will last longer if there's an automatic in front of it. My 4th gen rear died with a 6spd and a lot of street tire abuse.

IROC-Z Driver

Yea its and automatic. I'll try it out. So it will pretty much bolt in, with a few adjustments to brake lines and stuff? Sounds easy enough. Another question while Im at it, what about the drive shaft? is that something that can be reused? or will I have to change that out too?

DJP87Z28

You can reuse the stock steel one with no problems. But now would be the time to upgrade to the LS1 3" dia aluminum dr shaft.

Aaron91RS

iTrader: (2)

with regard to the 10-bolt
In the words of ludacris
stop, drop, kaboom!

IROC-Z Driver

Alright. Any good companies to look at for this dr shaft? Ill look around, thanks for the help guys.

Spiers

iTrader: (7)

The 3" aluminum driveshaft came factory on the LS1 cars. It's lighter and balanced better. Ebay, salvage yards, craigslist, and parts classifieds/want to buy are all good sources. A quick want to buy post on LS1tech would get you several choices in a matter of hours. They usually go for around $100 give or take a few.

Orr89RocZ

iTrader: (20)

i went 10.6's at 128 on a 1.41-1.45 60 foot on my LS1 10 bolt rear. 87 TA went 10.0's at 133+ on 1.38-1.4x 60's on his thirdgen 10 bolt rear

Some break on 13 second passes. I broke my 9 bolt with high 13 pass.... its all luck of the draw I guess. Auto's are easier on parts and should last longer. Manuals tend to break stuff. I know a guy that broke a 12 bolt rear with a LSx powered TA with T56 trans. Then again, 87 TA now has a T56 and has gone mid 10's at 134 with his but on softer 1.5-1.7 60 foots.

Basically you never know whats gonna happen. I plan to push mine into the 9's Once it breaks if it ever does, its getting a 12 bolt

IROC-Z Driver

Alright, I might know a guy that will sell me rear end and dr shaft for cheap. Like i said, pretty new to this stuff. Thanks for the help.