anthony714

basically i think hes saying if you get the 12 inch brakes you ll need 16 inch wheel right away,,the 15s wont bolt on them at all..and you should at least swap out your proportioning valve if going to disk from drum and also think about a new master....

85_305

How much does a new master cylinder go for? Do I need a certain type?
By time I actually get the LS1 rearend I will for sure have the 16" rims

anthony714

price a master anywhere,autozone,ebay,online services,your local napa,see what one for your car with disks goes for..some folk say you need them some say youdont,id personally would replace it being it probably would be under 100 if you loook around..never buy used brake parts and expect to use them as is

85_305

^Oh, ok.. so just get a brake master cylinder for a REAR-DISK BRAKE 1985 Camaro and that is good enough I have heard several people tell me this as well, so I am guessing that is my best bet.
So.. LS1 rear end; direct bolt in or not? LT1 rear end; direct bolt in or not?
Whichever is the most DIRECT bolt-in I am going with. Sorry to be reapeating myself; but I like to be absolutely 100% sure when making decisions like this

Drkhrse89

From the reading that I have done the LT1 for sure is a direct bolt-in. The LS1 rear comes with two brake lines from the caliper and you will need to get a T fitting to run a single line to your existing line.

I am not 100% sure on which master cylinder comes in the 85 Camaro, but I will not be needing to upgrade the master cylinder because in 89 they were the exact same in the disc cars and the drum cars. You will have to get a proportioning valve though. I am getting the Wilwood **** style since my friend is a dealer and I can get it pretty cheap. They are only about $40 anyway from Summit.

The LT1 rear should fit over the 16" wheel since that is what came on the car, but there might be small fitment issues if the third gen wheel itself is a smaller interior diameter than the fourth gen wheel.

I am still gathering information on the LS1 swap since I want to have everything lined up for when the time comes to do the swap.

anthony714

the lt1 and ls1 rear will bolt directly in w/o a hitch except for a possible brake line issue as stated before..all the brackets and shocks and springs that hold the rear in are the same spot in a 3rd or 4th gen..and as far as a lti or ls1 reart go,unless you have a PREFERENCE BETWEEN THE BRAKES I DONT THINK IT MAKES A WHOLE HECK OF A LOT WHICH REAR,I DONT THINK THERES ANY DIFFERENCE IN TERMS OF STRENGTH OR RELIABILTY..

85_305

This was my next question; thank you for answering it. I have heard that the LS1 rears tend to drop out of STOCK LS1's w/ hard launches. Since I will be putting out basically LS1 numbers, shouldn't I fear my rear falling out as well?

Drkhrse89, since the car has 200k on the *body*, I will get a new master cylinder just to be on the safe side. But if I get a new master cylinder, what do I get? Just one for a normal disk-brake rear 1985 Camaro?? Or one from an LS1/LT1 engine? If I get the one from a "disk brake 1985 Camaro", then I wont need a prop. valve right?

Drkhrse89

Yes you just need a MC for a disc car. I would say get the PV just to be on the safe side because you never know what type of braking your particular car will do.

I have several friends with 6 piston fronts, 4 piston rears that are running an adjustable PV because it was just not braking up to standards. And for $40 it is just good insurance.

Also Anthony is right there is no difference between our rear and an LT1/LS1 rear. They are both the same size gear and everything. However, like mentioned before, the 85 rear came with 26 spline axles and the 89/90 and up came with 28 spline axles resulting in a little bit stronger rear end. The reason I went this way was because I was going to be going to an LS1 brake system and found the rear complete for cheaper than just the brakes. That and I got 3.42 gears as opposed to 3.08 stock.

85_305

^Since I will be getting an LS1/LT1 rear w/ disk brakes, will my 85 stop better than stock? Or will it be near non-noticable?

Crovax WS-6

this is what my 300 HP Small block did to my 10 bolt. granted it had 164K on it when it finally let go. But still its not something you really wanna go through.

85_305

^My rear has maybe 60-100k on it; do you think it will at least hold the rest of summer?

Crovax WS-6

well i doubt you drive as hard as i do. And this was also behind a T-5 and bangin gears is what killed it. So you should be good. just No Neutral drops lol.

doug791

His is a t-5 as well (just correcting cause he seemed to think you have an auto)

Just dont dump the clutch out really hard and dont try to do things like really big down shifts. If you drive sanely your little t-5 and rear should hold for a summer. But save your pennies cause its just a matter of time

Drkhrse89

Yes it will stop better than stock. Even if you have discs all the way around due to the larger rotor.

Not trying to wish ill upon you. That is just awesome! Way to destroy parts.

85_305

Well my dad had the car since 32k miles before it blew out going around a corner. Instead of getting new gears like he wanted, the GM Dealer gave him an entire rear w/out him knowing. So the rear has quite low miles. Dad pu$$y-footed the car.
I dont plan on doing any side-steps, but getting on the car (as in "racing") should be ok? I am worried about getting taht power to the ground and having the rear pop.

Drkhrse89- What size brake do the LT1/LS1 rears use?