I have a 91 RS, Im getting a deal on a fourth gen rear, fourth gen seats (front and back), Fourth gen brakes, and all the suspension (front and rear). Im not sure what will convert over to my car. I think everything will bolt in, however im not sure what will be worth it or what it will take. My rear is a drum brake and im getting a disk 6 speed rear out of an LT1 car. Will i need new master cyl. or just a proportioning valve? Im more concerned about brakes and suspension. As my car is an f41 suspention package car and im not sure if the new susp will be better. Brakes? are 4th larger? better in anyway? a pain to change over? Any help or info will be appreciated, And any knowledge at all on converting anything 4th gen will also be appreciated. Thanks Brian

 

The following FAQ will answer most of your brake questions. The second will provide some insight on fourthgen parts compatibility:

https://www.thirdgen.org/forums/tran...-10-bolts.html

https://www.thirdgen.org/forums/body...-exterior.html

JamesC

 

The front suspension is entirely different in design. We have a modified McPherson strut setup whereas fourthgens have a double-wishbone design. Fourth gen rears are 2 inches wider per side so you'll need 4th gen offset wheels unless you like the trailer park look the 4th gen rear gives the car. LS1 brakes are good. Dont bother with 93-97 front brakes. If these are LS1 brakes you'll have to do a few mild modifications to your spindles to mount them, but it's not bad. You'll need a disc brake proportioning valve. Try to grab the one from the donor car. It might fit since you've got a late 3rd gen but I'm not sure. I know LS1 master cyls fit... so LT1 master cyls probably fit, so probably the prop valves fit too. There's no telling til you try it though. Or just read through the aforementioned links.

 

4th gen rear with stock 3rd gen wheels looks GREAT! Wider stance, but the tires still fit under the fenders, no sticking out. Apparently Vortex has not actually SEEN this setup & is making an assumption, based on the wider with.

And there is no NEED to swap the mast cylinder out. Some do but most people don't, and have no braking problems.

 

Stephen, it appears that once again you're confusing the master with the proportioning valve. At any rate, the issue isn't with the master, which can be used with either braking system, but with the proportioning valve. As I mention in the above FAQ, for best braking performance, use the correct valve.

JamesC

 

I typed Master out but read correctly & the fact remains.....

There are more people who swap the rears out without touching anything on the brake system (except the e-brake cable, than there are people who swap other parts, ,than there are who swap other parts to "support" a 4th gen rear. And they don't have complaints about their braking afterwards.

 

I've seen it PLENTY of times. In my opinion it looks trashy. The only way you can pull that look off is if you put some 10 inch wide wheels on there. When you have stock-sized narrow (245/50/16's are narrow enough for a 2inch difference to be very noticable) tires sticking out two inches farther in the back it just looks a bit silly. I've got nothing against a wide rear stance if you've got the meats to back it up.

Different strokes for different folks though... if you like the look of the 4th gen rear good for you.

 

To the OP: Reason dictates that GM manufactured different valves to maximize their braking systems. Use the proper valve for the system you're using and you can't go wrong. Get it right the first time.

JamesC

 

This looks trashy? (blue Camaro on the right) And the BFG 295/50s will fit on a stock 16 x 8 wheel, even without the extra room being needed. Been there, done that, back in the 90s.

 

Im sorry man, it looks crappy to me. Im not sure why you're so concerned about my opinion on it anyway. And just lining up with the fender isnt the only criteria either. You can tell the tires dont line up when you can see the face of both wheels on the side of the car. It just looks goofy.

 

Just that you termed it "trailer trash". What defines "trailer trash"? What IS "trailer trash"? Is it different than my house trash?

Most people seem to think they stick OUT, which implies the lowrider fit of the tires. They do stick out FURTHER, but OUT implies past the fenders, when obviously, they do not.

My 17" x 9" ROH Snypers with 285s sit virtually flush, like those do. Does that make my car "trailer trash", because of the tire fit?



Just because YOU do not like something somebody has or has done, there is no reason to insult or get derogatory. Just a different look, than what you like, that's all.

Sorry...I just really hate when people try to state their OPINION as a fact, of any kind.

 

Wow the butthurt is strong with this one. Since when does anyone see "it looks trashy" (I said nothing about trailer parks, that's all you) as anything but a subjective judgment? And trashy just means it looks cheap. It looks like you couldn't afford a part that fit properly so you used what was available. If that's your definition of "trailer trash", then whatever, but those are your terms, not mine.

And yours probably looks better than normal because you've got 9 inch wide wheels. It still looks a little weird, but wider tires go a long way towards making it look like it's not just a car patched together out of a bunch of parts that don't fit. But you can still tell from the side that it sits out too far. From the back it probably looks okay if you can't see the plane the face of the front wheels are on. It's not the tirewall's distance from the fender that makes it look weird. It's that the tires don't line up with each other. If that doesn't bother you that's fine. Go enjoy your car man. I've made decisions with my car that other people don't like. Whatever, life goes on.

I'm sorry my opinion upsets you. There's not really much I can do about that.

 

Damn, i didnt mean to start an argument, but thanks for all the info guys. I do have a set of chrome corvette wheels, 18x9.5 or 10. im not sure what they are exactly. but thats why im doing all of this. Do you think it would be worth just getting a willwood adjustable proportioning valve instead of playing with all the stock ones?

 

I personally think they are a good idea, on ANY car, if you take the time to test & adjust, test & adjust, test & adjust.....Not just put it in & "kinda get it good".

 

yea, i dont want to have anything fail or not work properly when going down the road or at the end of the 1320

 

The biggest concern with using a disc brake prop valve is that the rears will lock before the fronts which can get real ugly real fast. Some people just leave it... but I didnt really feel comfortable with that if I got into an emergency stop situation. You never know what's gonna happen.

Either way, you can get buy with a drum prop valve at your own risk... or you can do it right. Or you can get the adjustable one and be a step ahead assuming you get it set up properly.

 

thinking now about the cost and pain in *** factor i think ill switch to adjustable prop valve later on. not too long down the road. But for the record, I should leave the front susp and brakes on the other car. A the suspension is different and can not be converted over easily and B the brakes are relatively the same? right

 

Alum, single-piston PBR calipers are virtually the same 89-97, if that's what you're asking. Most would agree that rear discs are superior to drums. Should you be interested in the fronts, as Internal mentions above, the LS1, 98+, would be the best bet.

JamesC

 

I also read a thread one time about converting to C5 corvette front brakes, there is a bracket needed but you just have to drill some holes. It seemed pretty simple

 

You can research other choices in the following link:

http://www.flynbye.com/

JamesC