I saw some today and was wondering is this some kind of underground garage mod or can you buy these? ANd if so how good are they. I cant seem to find links to them either. I would love to be able to run 4 wheel disc and keep my ponies..
no there's nothing underground or ghetto about it. 5.0 resto sells them ( 4 lug disc conversion for the rear) as well as some other places. the only real reason most guys switch to 5 lugs is so they have a greater selection of rims......
I'll be getting these. I want to run ponies, plus I just found out about 18in ponies so I definately want to stay 4lug. Now if I can just find where to buy 18in ponies. But I have seen them with my own eyes.
Auto trans 87-88 Tbird Turbo Coupes come with 3.73 gears and manual Turbo Coupes come with 3.55 gears. Cost is $125-$300 for the rear axle. Add another $100-$200 or so to complete the brake upgrade.
I choose 3.55 since I do more highway driving. Both ratios have 10” disk brakes with vented rotors as standard equipment.
It takes 2 guys the first day to get the old rear end out and the new one bolted in place. It takes 1 guy another whole day to do the brakes.
You will need a several sets of fittings, I recommend that you get them from Matt90GT's website, http://www.svo73mm.cjb.net/. Read Matt's instructions thoroughly, everything you need to know about the brakes is all there. You need to be patient and follow all the internal links, and there are many of them. You will need 2 fittings in the rear to adapt your old brake tubing to the TC disk brakes. The fittings go between the steel tube and the caliper brake hose. You will need another set of fittings to make a 2 port to 3 port adapter. To make life simpler, just buy the kits from Matt. You could piece them together, but it's not worth the time unless you work at an auto parts store with all the fittings ever made.
You will need to drill the quad shock mounting holes 2” below the holes drilled for the Turbo Coupe mounting points. The bolts are metric, so don’t loose them or the nuts. A 15/32” drill should be about the right size unless you have access to metric sized drill bits. Going without quad shocks is not an option unless you have aftermarket parts to soak up the wheel hop.
You will need a proportioning valve, Summit has one for $40 + shipping.
You will need a kit (FMS makes the part) to gut the stock proportioning valve, Summit also has that, about $10.
You will need a new master cylinder, see Matt's site and make you choice. I used a 94-95 Mustang master cylinder. Note that rebuilt 94-95 Mustang master cylinders do not come with a reservoir. That means a trip to the junkyard and some more money spent.
Your brake pedal may be very hard and almost impossible to lock up the brakes. I had to replace the front calipers with 73 mm calipers from a 91 Lincoln Mark 7 to get the braking performance up to par.
Bleeding the brakes will require 2 people and some coordinated effort. I don’t recommend using you wife or girlfriend to pump the pedal – they get offended when you yell at them. I used a homemade power brake bleeder constructed from a garden sprayer and some fittings from Home Depot. It cost about $25 and was worth every penny. Do a search on garden and you'll find it complete with pictures.
jrichker
That seems alot of work for something that comes in a kit, but I amgoing to read through your link just for education purpose, maybe ill go tha t route if it makes sense to me.
Steeltechsolutions.com sells some brackets that let you put cadi or camaro rear calipers on and they include emergency brakes. ~$400 for a complete set up. You can also just buy the brackets and go junk-yarding to pick up the rest of the parts. I would put some MarkVII front calipers (73MM steel) with some good pads on the front and good shoes for the rear, and see what a difference that makes. Braking is 75% from fronts and 25% from rears more to gain up front than in rear.