C5/LS1 G-body Brake Conversion Questions

[86Cutlass383SR]

I'm sorry if I'm being redundant in my questions. I've read and read enough opinions to throughly confuse myself. Since I'm building a daily driven street car, this is obviously something I don't want to get wrong.

I'll be running the 13" Vette C5 front calipers and rotors with a bracket from Ed Miller on a stock g-body spindle. I may upgrade later to the S-10 ZQ8 (?) spindle but I don't think a differance in spindles will matter since I'll be using the same calipers and rotors.

The rear will be the 2000 Camaro LS-1 rear disc brakes with the e-brake hooked up.

Here's where my confusion begins. I also had Ed Miller modify a stock proportioning valve for my rear disc swap. Should I also run an adjustable valve in the rear line or leave it out?

I've read some guys recommend just running the front line to a "T" and then to each front caliper, and then doing the same to the rear with an adj valve in the rear only. I don't have a problem with this setup except I'd also like to have a brake warning light since this will be a street car.

If I understand correctly, I can use the stock master cylinder unmodified. I have no idea of the bore size. According to NapaOnline.com the new master for the 86 Cutlass is a stepped bore (24mm/36mm) and the remaned cylinder is listed at 24mm only.

I am getting ready to run all new brake lines. Do I need 3/16" or 1/4" brake line? (I think I've read 3/16" is best?) Any special adapter fittings required for this conversion? I got my front caliper/rotors from DiscBrakesRUs years ago and the setup included front braided lines. Okay to use these (still unused) or should I just run stock rubber lines? Vette or G-body?

Any other tips and/or hints in my swap would be very appreciated. I'd like to not have any surprises when I get this car on the road again.

Thanks

[a67]

...Here's where my confusion begins. I also had Ed Miller modify a stock proportioning valve for my rear disc swap. Should I also run an adjustable valve in the rear line or leave it out?

I've read some guys recommend just running the front line to a "T" and then to each front caliper, and then doing the same to the rear with an adj valve in the rear only. I don't have a problem with this setup except I'd also like to have a brake warning light since this will be a street car.

Thanks

Should not run two proportioning valves. This is the way I would do it: "running the front line to a 'T' and then to each front caliper, and then doing the same to the rear with an adj valve in the rear only."

For the brake light warning in the stock style combo valve. They are for the average driver that can't tell that his brake pedal is going to the floor. IOW, folks on this site shouldn't/don't need them.

Although, some M/Cs have a low fluid warning switch. This is much better then the pressure differential switch in the combo valves.

The 2000 Grand Am M/C is one that has the fluid switch. Has a 1" bore w/o quick take up. Has bubble flair fittings and LH exits.

I can't help with line size, but there is a 3 page thread on this topic currently being discussed.

Edit: you mentioned having braided lines. If they are correct fit for the vehicle/brakes I would use those over rubber lines.

Bob.

[monteboy84]

I'd do the ZQ8 spindles now, it's the RIGHT way to do the swap, as the G-body spindles really aren't built to adequately handle the C5 brakes. They spindles and hubs really aren't that spendy:
http://cgi.ebay.com/ebaymotors/S10-B...item3a57c924de

ETA: My point about the G-body spindles has more to do with the mount points you'll be using for the new brakes, than it does with the beefiness of the spindle itself.
ETA2: I just got my brackets from Tobin at Kore3 for the ZQ8/C5 conversion and they're fantastic, well worth the money!

[86Cutlass383SR]

I had planned on doing this swap, atlough later. Right now I'm trying to get this car running under it's own power. I already have the parts to do the g-body swap. After I get the engine in and decide ifI want/need to lower the front end I'll probably be doing a front coil swap and will be definately be swapping to a set of front upper tubilar arms from Marcus @ SC&C. I'll be doing the swap then. I have enough on my plate right now just trying to get it running again. I do appreciate the concern Matt

[monteboy84]

Fair enough, keep us posted on your progress.