Alrighty, so I think I have read every brake conversion topic in here, and I honestly think im more confused now then when I started.

I have a 87 GTA with the 4 wheel dics. The pass side caliper, on my car has been destroyed by some hack, and now it leaks brake fluid like no tomorrow. I pulled it the other day and bought the rebuild kit but there is no saving it the inner wall of the caliper has been badly gouged.

Now I looked at simply replacing the stock calipers on the rear, but the cheapest I could find them for was 200+. And i figured it wasnt worth it to replace the stock calipers, when I could upgrade using stock Vette, or Ls cars brakes. This is where I start to get lost. I have found alot of these topics are for the rear drum to disk setup, but i already have the rear disks.

I plan to eventually upgrade the front brakes but as Im currently layed off its not in the budget right now, as I would like to get the wilwood setup from Ed. That being said I would like the cheapest/easiest upgrade. I also am keeping my stock GTA rims.

Now I think (please correct me if im wrong) but both the C4 brakes and the LS1 brakes fit with no issues on the rears with stock GTA rims? I know 1LE is another option but due to C4's and LS1's being more prolific I have cut the 1LE option out.

Now to get the LS1 brakes to work, there is only one bracket that needs an extra hole drilled in it, swap backing plates and some fancy work with the brake lines to get the e-brake to work correct? Are there other issues to get it to bolt up, like spidles?
https://www.thirdgen.org/forums/brak...dding-ls1.html
Is the best search I have found, but the pics no longer work But he has the 10 bolt where as I have the 9 bolt. But i am largely leaning towards this setup for my car.

The C4 non-HD brakes, as they do not have hubs built in require quite a bit more machining/fabrication and work to get them to work correct? The spindles also require quite a bit of work to fit too correct? And was it the 84 to early 90's vettes or 88 to early vettes ? (i read both those on here)

With either of these options do i need to worry about changing my brake cylinder, or proportioning valve? As i know with the 1LE they both need to be changed.

I have access to both an 87 vette, and a 02 TA for parts so either way, what exact parts should I grab from either car?

Ok so I know that there is alot of questions and info that Im asking for but my head hurts from reading and I feel like im just running in circles. I just want the easiest option to bolt up to my GTA, and considering they are rears i dont need an incredible setup, just something better then nothing :P Thanks to anyone in advance that even reads all of this, let alone answers any of my questions.

 

Your EASIEST upgrade option, would to put 89+ PBR calipers & bigger rotors. Basically, you'd just b putting stock parts on, only larger stock parts.

If you want the LS1 brakes, you could just always swap out the whole rear end, for a 4th gen rear end. Simple, quick & may very well be cheaper in the end, over buying the adapter mounts, new rotors, calipers, etc.

 

It's my understanding that using the LS rear would extend your rear wheels by at least an inch on each side. Correct me if I'm wrong. Something to consider.

 

Yes..Out from where it is stock, but not out past the fenders.

I can't even tell you how often I hafta post these pics. AT LEAST twice a month.....I posted these pics just last week too.

 

Alrighty so I have been reading more and more info on all of this.

Pretty sure now that I am going the LS1 route.
I considered getting an LS1 rear end, but kinda turned off by the fact that the 10 bolt from stock LS1's is apparently worse in terms of durability then my 9 bolt. Maybe marginally, but I want to upgrade, not do a sidestep. And considering the shipping weight of a whole rear end vs just the braking system that saves me at least 400 bucks.

New question though, cant seem to find someone who has updated the 9 bolt rear end to the LS1 brakes, just alot of people who have done the 10 bolt rear end, and differences?

Oh and Stephen, thanks for the pics, what rims/tires are those? I must say I kinda like the stance....

 

The stock 16" wheels. This pic is from before the rear end swap, but same wheels.

 

I have a stock 87' 9 bolt with the iron calipers. Wouldn't i need the '89 backing plates before being able to install the aluminum calipers ('89 +) and bigger rotors?

 

Thanks for posting the pics. Yeah, you can tell the rear track is wider with the LS1 rear, but like you said, it's not a huge difference. Good job, and that's funny how often you've been posting those pics. Appreciate the effort to let people see the results.

 

I also have an '87 GTA with 4 wheel disc. A few years ago I did the ls1 swap in front, It was a huge improvement and super easy to do. stock master cyl was fine, I also gutted the prop valve, I also had to use a 1/4" spacer to clear the wheels. Even with the small iron caliper rears the car stopped awesome. The difference in strength bewteen 10 bolt and 9 bolt aside, the 10 bolt is a lot cheaper to buy parts for and to make as strong as 10 bolt. the gears alone for my 9 bolt were over $300 without bearings. same thing for 10 bolt is around half that if not less. Ed also has the brakets for the rear pbr swap for the 9 bolt, if you want to keep it. In other words, ls1 fronts, pbr rears, or ls1 rear 10 bolt assy, gets my vote. I have c6 z06 in front now, and I am still undecided on rears. have considered 10-bolt ls1 myself just for cost reasons. I have to narrow rear end anyway to fit my 315s. hope some of that helps. I teld to ramble on and on and on.....

 

PROBABLY, but don't get me to lieing on the specifics I don't know about.

 

Off topic but how do i add my own question i just signed up and cant seem to figure it out?

 

Nope....A stock rearend, with the right backspacing on your wheels, a little hammer work to the inner fender panel & you'll fit 315s....WITHOUT a narrowed rear end.

 

So you put LS1's on the front with only a spall spacer with the stock GTA rims?

And I was hoping that it was a simple swap to put LS1 rears on a stock 9 bolt rear end. Shipping a full LS1 rear end (there are none close to me) would cost more then the rear end itself.

If I have the LS1 backing plates and everything else does anyone know if its easy to fab them up to the 9 bolt? Dont suppose Ed's brackets work any better in terms of bolt up?

Dont really want to go with the pbr brakes, as they are still an older style of brake and getting parts/replacement is getting difficult or will be in the near future. LS1's are cheap and easy to replace.

 

I hear you, I would like to install the LS1 rear calipers as well. Let me find the backing plates that Ed Miller has fabbed up. There's a bunch of work he's been doing.

Ed, we need your input mate!

 

I already have the wheels, and the backspacing is wrong, bought off eBay. It would be easier and cheaper for me to narrow thevrearend than buy 2 new simmons 3pc wheels. Plus I have to put in new inner wheel wells in the rear anyway. And yes 1/4" spacer and stock wheels fit perfectly.

 

I agree Ed help! lol

But I know he has a backing plate for the 9 bolt, but its for the PBR rear brakes, and the PBR brakes are the same as the 93-97 brakes, which are different then the 98-02 LS1 brakes, so far as I can gather from all my reading. And the backing plate for the 9 bolt has been discontinued as far as I can tell as well. So need to find something/someone to make a 9 bolt compatable backing plate that the LS1 brakes can bolt up to....

 

Yes. The only difference between the 9- and 10-bolt PBR set-up is the backing plates, which are drilled a bit differently. The 9-bolt is on top in the following pic:

https://www.thirdgen.org/forums/atta...ar-bplate1.jpg

The Delco-Moraine to PBR swap in the following link is for a 10-bolt, but it may provide you with some ideas of how the swap is made:

https://www.thirdgen.org/forums/faq-...iscs-89-a.html

BTW, I've never experienced any difficulty in sourcing parts for my brake up-grades: 1LE fronts and PBR rears.

JamesC

 

https://www.thirdgen.org/forums/atta...ar-bplate1.jpg

Okay, i looked at your post, and it is very helpful. Was yours a 10 bolt? Is that why you mentioned the only difference between the 9 and 10 are the backing plates, but I'll run into the same issues you did? By the way, there's only 1 backing plate pictured in the link you provided.

Yes, this is very helpful. thanks for passing along. Would you have used different rear calipers knowing what you know now?

Can you tell me what PBR is? Is that the manufacturer? Were the iron calipers made by PBR?

 

Mine was a 10-bolt. There are two backing plates in the pic, one on top of the other to show the mounting hole differences between the 9- and 10-bolt. No real issues (While the 10-bolt used a shim to center the caliper over the rotor, my understanding is that the 9-bolt didn't require it). The brake lines, rotors, calipers, etc. are all the same. I'm satisfied with my choice of calipers, though to be honest, at the time I was swapping brakes, there weren't many options. PBR is the aussie manufacturer of the alum calipers. The iron calipers were made by Delco-Moraine.

JamesC

 

Welcome to TGO. Top or bottom of the page, left side "Post Reply."

JamesC

 

If price becomes an issue, check http://www.rockauto.com/index.php?a=...rtsgascappromo for prices. That $200+ seems outrageous compared the prices on rockauto.

JamesC

 

Im in canada, and our dollar is still way below the US. So even the cheapest calipers from rock auto are still going to cost me at least 180 bucks. And I have to pay to have them shipped to my US address, and pay taxes across the boarder, and my gas to get down there to get them. So its no cheaper for me, and I have a complete LS1 rear setup for that price, and none of the LS1 parts are discontinued, or will be any time soon.

I sold my daily driver to pay off my bills as Im layed off, it is gone this saturday, so I need my bird on the road asap!!! But i still want to upgrade instead of putting crap parts back on her.


So has anyone bolted LS1 rear brakes, to a stock 9 bolt rear end?? Do i need LS1 backing plates, or am I going to have to fab something up????

 

Ouch!

JamesC

 

Some of these threads will help.

I KNOW I've seen a m ember who fit LS1 brakes onto his 9-bolt rear.....I'm still hunting for that thread.

 

Thanks very much. I looked at the pic again and now see the two backing plates. This is very helpful to see all these details. Do you know if Ed has the backing plates for the 9 bolt PBR calipers? Sounds like there are more options for rear brakes now, what would you go with today?

 

As of Jan. 19, 2009....Apparently he doesn't yet.

https://www.thirdgen.org/forums/brak...-rear-pbr.html

 

I hope you find it, cause Im going nuts.

I have been hunting the 4th gen forums, trying to find someone who has done the LT1 to LS1 rear brakes (so far as i know the LT1s are basically the same as pbr's) and everyone there has done fronts. There are a few that have done rears but no one says how they did it, or if it was difficult, or what backingplates they used.

Arg!

 

It's not clear to me if Ed doesn't have the plates needed to allow for the c5 rotors, or the backing plates for the 9 bolt PRB setup.

 

http://www.flynbye.com/

Check out this, there is the backingplates in the catalog

 

WHERE?

Why not provide info/a link to the PART, instead of just to the whole site?

I see drum to LS1 disc plates...10-bolt to LS1 disc plates, but no 9-bolt to LS1 disc plates.

 

That wasnt the question 87camaroz28 asked.
Ed does have the backing plates for the 9 bolt pbr setup on there.

Thank you for your attitude though, was quite refreshing.

I posted the link so everyone can look, for the 9 bolt backing plates, 10 bolt backing plates, ect. Not a specific link incase someone wanted something different as this thread is broader then my specific needs. I didnt realise looking through his parts catalog was that difficult, so here I clicked for you...

http://www.flynbye.com/catalog/i60.html
is the LS1 rear disc conversion, but it doesnt state for 10 bolt/9 bolt ect.

http://www.flynbye.com/catalog/i31.html
is the 9 bolt disc conversion backing plate

But please read other peoples questions before you cop an attitude.

 

Put down your whiskey....

I HAD no attitude, but now I do. It was just a specific question of WHERE. A link to the main page & not even to the 3rd gen section? If you have THE info, why not provide it, rather than a general main page link?

That would be like saying..."The answer you want is on https://www.thirdgen.org

Half of Eds parts don't even specify whether they are for front or rear...drum or disc. He's put a lot of work into his products, but no so much into his site. Very hard to decipher specifics.

BTW...You posted a 9-bolt link for LT1/1LE plates, but he wasn't asking about those. He asked about C4/LS1 brakes.

 

http://www.flynbye.com/catalog/i31.html as listed above or

http://www.andyz28.com/3rdGen/reardisc.html

I'd probably still go with the PBR's, since I'm **** enough to want the rears to look like the fronts.

Whiskey,

89-97 PBR's are essentially the same.

JamesC

 

Thanks James, I thought that the 89-97 were pretty much the same, thats why i wanted to look to see if anyone had done a LT1 swap to LS1 and what they had to do. Then I could see what i need to swap mine to the 89 style, then to the LS1 style, kinda follow the trail lol.

I think i might just call ed, see if I can just talk to him get everything all figured out. That way I can ask Ed about the kits on his site. Althought it looks like he he states if the are for rears, if it doesnt say id assume its for the fronts for anyone looking at his site.

 

lol. I felt the same way trying to find what i need on this message board. I found everything except for the 9 bolt PBR conversion. I do appreciate the help that people are trying to give. Because there are so many combinations (thanks to the factory) of rear ends, brake design, etc it's sometimes hard (okay most of the time!) to get to the exact parts needed for your application

 

The LT1 to LS1 swap would seem to be hardly worth the effort--with perhaps the exception of the better e-brake on the LS1.

JamesC

 

Believe me, I appreciate any help someone is willing to give, especially accurate information. Like many people on here, i work full time, and have kids, and unfortunately time is not on my side...so any help in the right direction is a bonus for me. you are right though Whiskey, i did specially mention the 9 bolt backing plates, that's what i'm looking for. And LOL, thanks for looking for the specific links for us! Great job!

 

Yes, I agree speaking to Ed directly would be your best bet. We all have different needs, and when it comes to spending hard earned cash, you don't want to be sitting on your cement floor swearing because you realize you don't have the right parts!

 

Thanks James and Whiskey. These are the exact links that i neeeeeeed! Thanks so much. I'm thinking maybe to try and get a kit that not only has the backing plates, but also the calipers. Spohn has some nice cross drilled rotors. I think i'll need to custom bend the rear brake lines.

 

Nope. New lines, both hard and flex, can be purchased. You can find the part numbers in the conversion link I posted earlier.

JamesC

 

Well I called Ed, he is going to try to get back to me tonight! Better then I hoped for as I can just guess how busy he is lol

But incase anyone else is going to want to do this ill post up everything I find out and if it pans out Ill post up a step by step with pics for reference.

Cement??? lol thats a luxury! i get an old asphalt driveway

 

I found a few guys that did the (Full) swap, apparently the LS1 brakes are much better then the LT1 (this is all hearsay from other forum members) and that they actually stop from 0-60 in 119ft for LS1's, 118ft for C5's, and 136ft for LT1's and thats an average of 3 stops from a single guy. lol random tidbit I picked up somewhere.

i would love to eventually get the LS1 fronts, so would like the LS1 backs to match

Besides, I like the idea of my brakes saying Trans Am on the caliper

 

\

Yes, different backing plates are needed.

Ed

 

C5 rears no, 9 bolts with '89-97 PBR calipers yes. I'll be working with the C5 rear setup later this week as I have a little more time available this week. I'll post up what I find.

And since there's some confusion, I'll clarify a few things.

1- LS1 rear discs will bolt right onto 10 bolt disc rears
2- LS1 rear discs can fit onto drum rears with mods done to the drum axle housing ends
3- LS1 rear discs will NOT bolt directly onto 9 bolt rears due to the different axle end bolt patterns but MAY if you modify them, I haven't tried this and feel no need to. Go with the one that fits your specific axle and save yourself the work involved, life's too short.
4- The front brakes will do the majority of the braking, the rears merely compliment them. Again, install the brakes that will work best for your rearend and application and go from there.

I will update the site due to feedback received above.

Lastly, I apologize for all delays in responses to e-mail and PMs, I'm a tad busy now and will be until late this month. I appreciate your patience.

Ed

 

Ok so apparently to adapt LS1 rear brakes to a 9 bolt car, all you need to do is elongate the holes in the LS1 backing plate, and put in a 1/4" spacer to hold the axle in place to stop it from moving. Gonna try it, see what happens. If all goes well I get new upgraded brakes for 200 bucks

Thanks Ed, by the way for getting back to me, and for the clarifications