I have an 87 z28 that i wanna upgrade the brakes. I have been looking at the 1LE brakes that came on the 88 and up 3rd gen. Reason being 1LE package is cause it will work behind 15" wheels. Is the any other option that will fit behind a 15" wheel?

 

A 1987 Z28 came stock with 16in wheels. All 1LE cars also had 16in wheels. Why use 15s?

 

Cause I am running convo pro wheels.

 

The 87 IROC received 16" wheels, but the 87 Z28 received 15" wheels, the same wheel offered on Camaros throughout the generation, beginning with the 82 Z28 and continuing through the 92 RS. GM sure got a lot of mileage out of that wheel.

The Convo Pro wheels look like a nice, era-accurate wheel. But while 15" might somewhat limit your choices of brake upgrade options, the depth of the face of the wheel might require the use a spacer or adapter to keep the wheels from hitting the new calipers. That's not a big deal, just something you might want to prepare for. Have you fit the wheels onto the car or axle yet?

Will all of this be going on the 9-bolt that you're preparing? If it's an original 3.70 9-bolt, then it came off of an 85-86 Trans Am, which means it would've had, or still might have, the old Delco Moraine iron metric calipers. But the 9-bolt will accommodate most brake upgrades, except the late 4thgen "LS1" brakes, so find one that will work behind 15" wheels.

The most economical upgrade would probably be the "1LE" PBR rear brakes you asked about, which are virtually the same as the 93-97 4thgen LT1 PBR rear brakes, but the LT1s are probably going to be easier to find, maybe cheaper too. And if you have junkyards nearby, 4thgens are a dime-a-dozen these days, so you might find some that still have their rear brakes. I've never tried to confirm that they'll fit with 15" wheels, but it's been said here on TGO that they will. Backing plates for the PBR conversion on a 9-bolt can be had from www.flynbye.com

If you do find some at a junkyard, you might think about grabbing the driver's side axle hardline, too. The stock hardline on your 9-bolt, if it's still there, is odd, in that it's a hardline all the way into the caliper, so it will only bolt-up to a stock caliper. Here, too, not a big deal, just something you might want to prepare for. Your stock passenger's side hardline will be fine as it is. New hardlines are available and inexpensive, but even a new one for the driver's side for 82-88 axles will be screwy and inaccurate, so best just get one from a junkyard car that you know will fit the upgrade.

Wilwood offers its own excellent 1- and 2-piston versions of the stock-style metric 154 calipers that are bolt-on replacements. Pricey though. But their rear replacement doesn't come with a parking brake, so if you want to retain a parking brake, then you'll have to keep your stock-style rear brake calipers (existing or new remanufactured) or go with a rear upgrade that gives you a parking brake, such as the 1LE or LT1.

Big Brake Upgrade is awesome too: www.bigbrakeupgrade.com I don't know if he offers an upgrade that will fit behind 15" wheels, but you could try contacting him. His name is Scott, and he's very helpful to anyone with brake questions.

 

For the front brakes, I'd be surprised if the 1LE brakes will fit behind 15" wheels, but maybe. The rear, I can see, but the front? I dunno. I'm sure someone will come along and confirm or deny that. But I'd be even more surprised if you could FIND a 1LE front upgrade. You might be limited to your existing or remanufactured stock calipers/brakes, or the Wilwood calipers I mentioned in the above post. That 2-piston stock-fit replacement Wilwood caliper is excellent. Expensive, but not unreasonable for the quality. Wilwood Disc Brakes - Calipers Description

 

Yes the brakes that I am asking about are for the 9 bolt that I am working on. Yes it did come with caliper brackets but no calipers or hardlines. But I have noticed that hawks sell the brackets to mount the 1LE caliper to the 9 bolt. I have also located at Autozone all the 1LE brakes from rotors to calipers for front and rear. So i am probably gonna get them and try and see if they will work on tge front and rear. Only thing is getting myself a core or 2 for the rear to turn in.

 

Cool, sounds like you're getting everything together. I was going to mention Hawk's has those backing plates too, but I'm not a big fan lol. I believe Hawk's also sells the e-brake cables you'll need for that rear upgrade.

Cores might be difficult to find, but maybe you'll stumble onto some later that you can return for the refund. LT1 calipers are awfully similar and will be much easier to find. Doubt they could be passed off as 3rdgen calipers, but maybe. Sometimes people here on TGO will have cores for sale in the Classified forums. And there's ebay.

 

Yeah i was writing up a list of parts last nite and like any project the list keeps getting longer and longer. Pretty much a core I am gonna well try and find another caliper and throw it in the box. Not like a part store know what i am handing them back lol.

 

Does the 1LE rear end bolt up to the stock torque arm suspension or do you need to fabricate new mounts? Is it any different in length, wheel to wheel? Do you need a new driveshaft for it?

 

1LE is just the brakes, "Performance Package" brakes, not the axle. The brakes can be installed on any 3rdgen axle, with conversion parts that are specific to each type of axle, such as your 87's. Conversion parts are available here:
Product Listing (flynbye.com)

 

There's no such thing. It's the same as all the other 89-92 10-bolt rears.

It always tickles me to see people asking about whether their [arbitrarily small] wheels will accommodate some [arbitrarily large] brakes. THIMK PEOPLE: if a wheel fits xx" tires, that means that the inside of the tire bead, is HALF THAT FAR from the center of the wheel. For example the INSIDE of the tire bead of a 16" wheel is 8" out from the center. "Large" brakes are large because THE ROTORS are large. So, the 89-92 rear discs use a rotor that's just shy of 12". That means 6" from the center of the wheel. The inside of the caliper has to have some amount of clearance to the edge of the rotor, then the outside of the caliper has to have some amount of clearance to the inside of the wheel, then the wheel has to have some thickness, and then it has to have a bit of clearance so you can put a tire on it. So, if you have a 16" wheel, that's 8" from the inside of the tire bead to the wheel center; give up about ½" to the outer surface of the wheel so that a tire can go on; the wheel might be 3/8" thick or whatever; you're down to around 7-1/8" for the inner dia of the wheel. Take out a bit of wheel - rotor clearance, let's say ¼"; a caliper is, what, ½" thick BARE MINIMUM where it goes around the rotor; then another ¼" from the inside of the caliper to the rotor. You've used up EVERY BIT of available space in there, with all of 1/8" to spare. NOW, the $64,000 question is, is ANY wheel less than 16" going to go over that? Not no, but HELL NO. Not unless that wheel has enough positive offset and/or is narrow enough that it doesn't have to go on as far as that part of that rotor and caliper. In fact, some 16" wheels supposedly won't even fit over those brakes; the 16" "crosslace" Firebird wheels from earlier years are said by people who have them (I don't, so this tidbit is 2nd hand) to be shaped in their inner diameter in some way or to have some feature, that they hit that caliper.

Bottom line: if ya wanna run small wheels yer gonna be stuck with small brakes. If ya wanna put on big brakes, ya gotta get big enough wheels for them to fit inside of. Not that complicated, folks.