Aerosmith

I'm putting a Strange master cyl(manual) and Wilwood 4 piston front brake kit on my 82, it already has a 9" Moser with the 11" drums in the rear. I run 275/15 drag radials rear(9" slicks at the track) and 165/15 skinnies on the front. The master cylinder has a larger volume in the rear chamber than in the front. Does anyone know if the drums or discs require the additional volume? I have looked at every tech chart in Strange, Wilwood, Mark Williams, and others and cannot find anything on this.

Also, Mark Williams recommends an adj proportioning valve on the front brakes when running skinnies up front to put more braking to the larger rear tires, anyone know if it makes a difference whether the line lock is before or after the prop valve in the system?

Last, stock line size to drum brakes is 1/4", should I keep the stock size or go down to 3/16" on the rear like the front uses?

My theory is that by virtue of the factory using the larger size line on the factory drums and the smaller on the factory discs, that the drums must need more volume and the discs less volume and more pressure. However the 4 piston calipers will have a much larger volume than the stock single piston calipers, about 270% I think so I don't know. I wouldn't think the placement of the prop valve and line lock would make a difference.

Any informed help is much appreciated!

AlkyIROC

Large volume is for front disks.

Big, White & Sl

I don't know about a disc/drum combo, but my car is 4 wheel disc and I just bought the Burkhart manual brake conversion and they told me to run it without a proportioning valve.