I have a metering block (I guess that's what you call it) that attached to the the master cylendar and then the lines come out of that block to the brakes. I switched from manual drums all the way around to power disc fronts, drum backs. Should this black stay or go, and where would the adjustable prop. valve go? Right after master cylinder before going into the block or after coming out of the block before going back to the rear brakes?

Put the proportioning valve after the "block" before the rear brakes

The front brakes on my 68 were replaced with disk brakes from a 70 Chevelle sometime before I bought it. When I test drove it, there was little front brake and way too much in the rear. After getting the car home, I took it to a friend's brake shop to install a proportioning valve. He wouldn't let me do it. He claimed that he has only seen one or two cars "ever" to need a proportioning valve. He adjusted the brakes himself and the work perfectly. I have no idea how he adjusted it, but it took him about a half hour. He claims people with proportioning valves never get them adjusted properly. Food for thought....

Here's a must read for everyone with a proportioning valve question

www.chevyhiperformance.com/chevyhighperformance/techarticles/71398/ (http://www.chevyhiperformance.com/chevyhighperformance/techarticles/71398/)

I put my proportioning valve in the rear line between the master cylinder and the distribution block when I did a manual drum to front manual disc swap. It works fine there too.