Technical 1946 chevrolet 3/4 ton power brakes

Has anyone been able to mount a power brake booster on the frame where original master cylinder would go? I am running the factory 8 lug drive train with front disk brakes and rear self adjusting brake drums off of a express van.

I'm thinking about using this master cylinder. I'm just not sure what size brake booster I need. I'm mounting the brake booster under the floor pan in place of the stock master cylinder.
http://piratejack.net/gm-universal-aluminum-master-cylinder/