[70STOVEBOLT]

I'm no expert, but since the OP has the Delco-Moraine style booster, he may need the appropriate master cylinder to match it. My truck has a Bendix booster, and I am using the master cylinder pictured in post #8 on top of the ACDelco box. I added disc brakes to my '70 using 1971 model year info to get parts. I am using the stock cast iron combo valve. The booster was a used part I bought off the parts board many years ago when I still had the drum brakes all around. It worked fine with the stock drum brake master cylinder. Hope this info helps, rather than adding confusion.