Drkhrse89

I have not seen anyone with the 26 spline axles have their rear end hold up to much at all. I personally would not be putting money into gears and a girdle with those axles, of course that is just my opinion. I am sure that you could find a complete brake to brake rear for around $150 and if you look hard enough you could find one with 3.73 or even 4.11 for not much more. I saw a 3.73 10 bolt with Eaton posi with about 30K on it for $250. When I was checking the girdles they were $130 and the gears would be what another $100 or so plus the install kit. You are looking at a decent LS1 rear with great brakes and 3.42 gears. Like I said before I picked mine up complete for $200 and 3.42 gears.

masiroc566

Hi...I have 330+hp with the 350 motor I placed in my car. I kept the 10 bolt rear and added a Auburn posi and 28 sline axles. The rear came with 3.42 gears and I decided to keep them. You can find excellent deals on Ebay you just need to have the time and patience to look. I found a set the new Auburn posi, 4.10 gears and bearings for $499. I kept my old gears and sold the 4.10's....Good Luck!!

85_305

So an LT1/LS1 rear would be a direct bolt-in for my '85, or no?

doug791

i keep telling you man tgo is your friend
http://www.thirdgen.org/newdesign/tech/4thgenrear.shtml

Just about anything you could ever want to know can be found either in the tech section of the www.thirdgen.org main page, or by doing a search on the forum at www.thirdgen.org/techbb2

85_305

^Thanx for the link to the axle swap
Any idea how long it would take?
How much do you think someplace would charge to have this done?

DevilsAddvocate

I wonder why i never thought about this...so basically we can get a 4th Gen 12 bolt or 9" as well huh

85_305

^Hell yes you can. I knew that, I just didn't know how much
effort/time/modifying/ money it would take to actually do it

anthony714

yes you can bolt any 3rd or 4th gen rear into any car,but keep in mind a 3rd gen rear is roughly 3 1/2 inch narrower than a 4th gen..meaning you stick a 4th gen on a 3rd,your tires will stick out almost 2 inches or you need 4th gen style wheels with more back spacing on them...nothing wrong with going to a wider rear,actually better,but now with new wheels your price went up.and the swap is easy

85_305

^Hmm.. you seem to be "in the know". Mind telling me the steps neccessary for the 4th gen LT1/LS1 swap? (are they the same rears or not??)
Thanx anthony,
Matt

anthony714

not quite sure why he recommended a ls1 rear except that i beleive they came from factory with 28 splines and an eaton posi..so its a bteer start,,fyi there a guy selling brand new 2002 rears with the zexel torsen diffs set up for disk brakes on ebay and he aint asking much and they are selling cheap,well at least for a brand new rear...but as far as a swapif you can take your old one out,the new one will bolt in the same way,with exception of possibly brake lines depending on what your switch to ..heck support car on stands,remove u koint retainers from yoke,dont pull drive shaft out of trans unleess you want it to drain on your drive way....support rear with a big jack,un hook lower stud on shocks,unhook flex line from floor board to housing,then lower jack slowly to the point you should be able to remove springs by hand.then re support rear,un hook panhard bar from diff,unbolt sway bar,id go from the rear,dont mess with the end links unless you wwanna replace them,unbolt rear of lower control arms from housing and whalla its out..reverse steps for the ls1 and its in.....if you got rear disk already then the only thing you might have to swap is a longer flex line to tie into the new brake lines depending on location and also depending on the years or rear and car the old car will use standard fittings on the brake lines while the newer rears will have metric fittings.theres adaptors if need

85_305

^So it truly *is* a direct bolt-in? Will the torque arms have to be switched around? Or the d/s length? Or ANYTHING else? What is the name of the seller selling those LS1 rears?

anthony714

bolt in...with exception of brake plumbing...item #7965136404,,look there.also on 3rd gen ,i think his name is 92anniversaryz or something like that,out of palos ,il...he bolted a 4th gen rear into his 3rd gen..ask him..

85_305

Hm..
What would the better, easier, and more cost-effective solution be; LT1 or LS1 rear end?

Drkhrse89

The one thing you need to keep in mind with the LS1 rear are the brakes. They are not going to fit under a 15" wheel if I remember correctly. Both rears are the same internally the difference is in the brakes and lines. The LS1 rear came with dual lines so you will need to T them off and then connect it to your existing lines. The LT1s did not. As far and putting it in it is a direct bolt in, the 4th gens and 3rd gens have the same length torque are, driveshaft, control arms, panhard rod, etc. Like I said before the only thing you will have to "retrofit" will be the brake lines and e-brake line, if you use it, and that is not very hard. You can find a bunch on information on www.thirdgen.org.

I am going to be trying my wheels on the rear when I get my new diff cover.

85_305

^Wait a minute, I have drum rears right now.. will that be a problem? That is one of the reasons I was looking forward to the LT/LS series rearend, not ONLY a posi, but disk brakes as well.
I will prolly be getting a pair of 16" IROC rims by the middle of this summer, so I am not too worried about wheel size (unless you need larger than 16")
So to summarize what your saying, I *should* buy the LS1 rear end. It is basically bolt-in, except I will have to play around with the brake plumbing. Am I following you correctly?