I have recently done the disc brake conversion on my 68 with manual drums. I just did discs on the front, not rear. I want to make sure i am running the corect components. I bought power booster with disc/drum MC, found a 'valve' off a 69 (one that hangs off the bottom of the booster, and kept the block that is on the frame rail that was used with the drum setup. I hooked up the brake lines and it seems to stop ok, but not sure if im getting too much 'nosedive' or if its normal. Im just not used to power discs and want to know if my setup is correct.

Thanks
Bubba

The block on the frame rail is only a junction block. It is not a combination valve, or proportioning valve as some people call it. The bullet valve used in 69 is known as a metering valve and was designed to delay fluid pressure to front discs until rear drums could catch up.
However, in 70 and later, GM dropped using that metering valve and went to a combination valve on the frame rail(but sometimes seen hanging below master,say in late 70 camaros). The combo valve does at least one additional valuable thing. It acts as a residual pressure valve to hold 10 pounds pressure in the rear lines at all times so they can react quickly when they are called upon. I suspect this reduces nose dive. In 69 the residual pressure function was performed by a valve inside the stock master. It is described in my 69 chassis service manual. But I am told later masters dropped putting these residual valves inside as the function was taken over by the remote combination valve. So if you have a newer master than 69, you may lack the residual pressure retention feature, so you may have more nose dive than some. Go to mpbrakes.com for lots of good info in this area. When I did my conversion on my 69 this spring, I went with a used combo valve that I bolted to the frame near the old junction block, and get no nose dive and great brakes. But I also put 11 inch drums on the rear to replace the 9.5 stock.