Formula 305

BACKGROUND:

Ok guys, so here is my story. I have a '90 Formula, 305 TBI, T-5 (originally an auto car), and a 10 bolt rear with drum brakes.

I am working on putting a rear end together for the car, I have a Torsen limited slip out of a 99-02 Trans Am, 28-spline axles from summit, for a 90-92 car, all the bearings, seals, shims, ect.

I have a 88 10-bolt rear end that I got with the iron Delco disc brakes, I thought I could use these brakes until my axle shafts showed up and I realized they wouldn't fit in the rotors, so those brakes are out.

PROBLEM:

So my problem is that I'm ready to put a rear end together, but I don't know what I'm going to do about brakes now. What I have for housings: 90 10-bolt with drum brakes, 10 bolt out of an 88 with disc brakes.

Ideally I would like to upgrade to rear discs, but since I thought I had brakes that would work I didn't budget for new rear discs and now I don't really have a lot of money for parts.

Ideally I'd like to put the PBR rear discs in the car, but definitely can't buy all the parts new I'd need for the swap. I know brakes from an 89-97 camaro, or 90-97 bird would work, but I'm curious what other cars I could possibly get these brakes from. I know some S10s came with PBR brakes, but I'm not sure on the years. I'd like to just get everything I need off a donor car, including backing plates.

Plan B is to re-use my drum brakes for the time being, and upgrade to discs down the road when the budget is there, but that kind of came crashing down when I noticed how radically different the backing plate mount to the axles were.

So I'm looking for advice on what I can scavenge PBR brakes off of, or how I may be able to fit my drum brakes onto a disc rear for a short time (this season, until winter comes). Also, since the car is now a T-5 a parking brake will be a necessity.

I appreciate any advice that can get me laying 11s sooner

Thanks,
Matt

Formula 305

Well I'm impatient & I just bought LT-1 rear brakes of eBay

thomas1976

Well done!

Formula 305

Just realized I haven't updated this. Got in my box of PBR rear disc brakes. Bolted the backing plates onto the housing. Friday, May 2nd I dropped the axle housing and a few big boxes full of parts off at my dad's friends shop to put the rear end together. I should have the built rear end back in about a week.

I still need to order a long list of parts before it goes in the car, but I need a day off to do that. First I need to figure out my car insurance because, apparently, since my car is titled to me, but registered & insured to my mother, if I have a comprehensive claim, like creaming a deer, I may not be covered. So I either need my own insurance or to transfer the title into my mom's name.

So after I straighten out the insurance fiasco, I still need a brake proportioning valve, brake lines, e-brake calbes, speedometer gears & sensor, and eventually need to wire in the clutch safety switch.

Formula 305

Also, May 12th I'm supposed to start my new job, so funds for car parts will be plentyfull & I can shift this slow & painful car build into... MAXIMUM OVERDRIVE!!!!

00JoeZ28

Will the LT1 rear disc brakes work on a 3rd gen with a stock rear end? I'm not to savvy when it comes to brake conversions so please excuse my lack of knowledge on this subject.

TTOP350

iTrader: (8)

Yes. 89-97 will work.

Formula 305

LT1 rear disc brakes are the same as 90-92 rear disc brakes

Formula 305

I'm bad at keeping this up to date, lol.

So Wednesday night I got confirmation that my rear end would be done thrusday or Friday, so Thursday after work I removed the axle & transmission.

Friday was my brothers birthday so I didn't make it to the garage, Saturday I split the transmission and did the speedometer gears, installed the 4 wheel disc proportioning valve and installed a new clutch master cylinder.

Sunday I made hard brake lines for the rear end and did some wiring that I've been putting off (clutch safety switch & reverse lights)

Monday the rear end went back into the car, put the torque arm in the mount & seated the springs.

Today is Tuesday, I tightened all the control arm bolts, connected the rear brake hydraulics, driveshaft, ect.

Went to put the ebrake cables I bought on & they don't want to fit. I bought cables for a 90-92 since I thought they were the same as the 93-97 rear brakes but the end won't slip over the arm on the caliper... Getting close tho. Ebrake or not, I'll be driving the car tonight

JamesC

iTrader: (5)

89-92.

JamesC

Formula 305

89-92 for Camaro
90-92 for Firebird if I'm not mistaken.

JamesC

iTrader: (5)

Any thirdgen equipped with J65 brakes, 89-92, got PBR's.

JamesC

Formula 305

The firebird officially has posi-traction and four wheel disc brakes

The speedometer works, but is 5 mph high at 55

thomas1976

Pics!

Formula 305

I'll have to see what I have for pics. I tend to forget to stop & take pictures. I have a few on my phone of when the old rear and the transmission came out, but that may be it...

thomas1976

No problem, I understand you very well, most of the times I'm to busy to take pictures too.

Formula 305

Here's all the pics I took...

Old rear end is out (Thursday Afternoon)



Transmission is out (Thrusday Night)
"I can see my pressure plate from here"



Transmission is apart, changing speedometer gears (Saturday afternoon)


Drove the car to work this morning, still a little air in the brakes, but for the most part it drives well, switched cars with dad at lunch & he had the car inspected at the dealership he works at

Got home from work, picked up the few remaining tools scattered around the garage, then went for a ride to "test" the posi on the wet roads