Not going to keep the 9"ers, so I am looking for custom C5 front/C4 rear brackets/adapters. I have the front brackets and calipers but am still missing the rear setup and master cylinder.

I don't sell anything, but having done this recently I can offer some advice. This is all assuming that you have an 84-87. I don't think Corvette calipers on an 88 are very common, the 88 calipers will work with bigger rotors as is with just some adapters. DoubleC4 sells both front and rear brackets for this setup, plus concentric rings. He has recently posted a sales thread,

DoubleC4 brakes

He also includes a howto link.

I didn't follow their advice for master cylinder or parking brake.

For Master Cylinder, I got one from a full size 94 Blazer w/vacuum boost. Just swap out reservoirs and it is a bolt in. Cheap and in stock at Rockauto or any parts store.

Parking brake cable solution I used is here -

Parking brake solution

Just make sure you get rear calipers with both brackets. Most of the remans have only the mounting bracket or none it all. There is a parking brake cable bracket you will also need. This setup is as close to bolt in as you can get and cheap too.

One issue I have is this really increases the front brake bias. I am investigating options to remedy this.

Awesome I will get a hold of him.

There are 2 different bracket needed at both calipers, for a total of 4.

Here is picture of just mounting bracket included -


Here is one with both brackets plus the spring that are needed -


As you can see on the second one there is another bracket opposite the parking brake lever. That is what the outer end of the cable sleeve mounts in. As I said, most remans don't include this part. This is the exact one I bought, it is available at Rockauto, and possibly eBay. The ones that Advance carries only have the mounting bracket. If you bought those, you would need to source the other bracket to use the parking brake solution in the thread I referenced.

As far as proportioning valve, I was going to disable the built-in one in the combination valve by removing the piston and spring. I was then going to weld up the hole in the plug. I believe that advice came from WCF. If it then has too much rear bias, I will do as you suggest and install a manually adjustable proportioning valve.

Ok cool. Didnt mean to be spoon fed but ive never seen an ebrake setup like that. Going to check rockauto right now.

I have the master cylinder and the rear calipers. I also have the from calipers and a s10 booster if u are interested u can email me mtkrusmark@yahoo.com