Dual master cylinder proportioning valves/distribution block

I am in the process of converting my truck from the stock single cylinder master cylinder to the dual master cylinder. I have picked up the Wagner#F66857 dual type listed in the online manuals but, now I am trying to figure out the proportioning valve/ distribution block.
What proportioning valve/distribution block are you guys using for your dual setups? Someone wrote that the block off a '70 Ford will work. Any others?
Are you using the original brake pressure switch? Or are did you change to a pedal mounted type?
The pipe fittings for this F66857 are much larger than the stock lines. Anybody have any problems with braking performance by using adaptors to reduce the fittings down to the stock lines?

Thanks,
Brian

I pulled the distrabution blocks off of an old international. As far as I know they are correct, but I wont know for sure untill I have it trail worthy and can test them real well.

You don't need any prop valves if you're using 4 wheel drums and you've matched that with a drum/drum master cylinder.

Chris

If you're using the Corvette non power unit w/power booster, you dont need a prop valve. I ran the front to a block with the pressure switch and ran the rear master cylinder outlet to the rear of the truck. Fresh turned drums, new pads, and she'd lock up all four 37x13 boggers on blacktop.