measuring for brakes

Ok heres the setup, I recently bought a 81 vette that has already been fitted with a narrowed 9" ford rear. very nicely done with qa-1 adjustable coilovers and 2" inset trailing arms. he was setting it up for a drag car, and I have designs on a pro touring car with a solid rear axle...LOL Question. How do you measure for the correct disc brake setup for the rears? I have measured from the axle flange to the housing, and none of the available kits seem to be the right depth. Some are close, but not exactly what I need. Is it a no go to add spacers to the back of the bracket where it bolts to the axle flange?

PM VM member brngrhd he has a 9" Ford rear end......

snakeater said:

Ok heres the setup, I recently bought a 81 vette that has already been fitted with a narrowed 9" ford rear. very nicely done with qa-1 adjustable coilovers and 2" inset trailing arms. he was setting it up for a drag car, and I have designs on a pro touring car with a solid rear axle...LOL Question. How do you measure for the correct disc brake setup for the rears? I have measured from the axle flange to the housing, and none of the available kits seem to be the right depth. Some are close, but not exactly what I need. Is it a no go to add spacers to the back of the bracket where it bolts to the axle flange?

Click to expand...

That is an interesting question for me also, as I have longer bolts and some nutz used as spacers for the Ford backing plates onto the GM axle on a camper/motor home....about 1/2 inch space to effectively move the shoes outboard into the Ford drums....

it seems ok so far....

sorry to hi jack the thread...but just for general information....:clobbered:

I am really concerned with this before ordering rear disc brakes for the car. While I would think that a little spacer would be fine on something that is not beat on, this car will be pushed hard on the autocross track. Also the rear has 3/4" wheel studs (5/8-18 threads) they are very beefy. the wheels I have chosen to go on the car are only 1/2" so I have spent the last hour or so milling them to 3/4. Milling them so that I am sure they are properly located,concentric and round. I would hate to have a vibration because of this. I will post a pic when I get them on the monster mosers. It looks very industrial and heavy duty, I love it.

found a solution to this problem. Went to my local dirt track supply store(speed shop) and they have weld on rear disc brackets cheap. to the tune of 15 bucks each. This solves the spacing problem. they use metric gm calipers from a cadillac rear or wilwood aluminum racing calipers. i chose the wilwoods and a 11" rear rotor. Moched it up on the axle today and it will work out perfect. Snakeater