Factory Brake Booster with Disc

[chevyguys]

Anybody have any experience using a factory 66 power brake booster with Disc/Drum brakes? I Bought the CPP grandslam drop kit with booster and master cylinder. It fit's horrible. Once everything is bolted up you still have to somehow seal the original 2"hole the mastercylinder used to fill. The new CPP booster and dust boot sit away from the firewall and just allow weather, heat, fumes and noise to enter the cab. I know I could probably buy a boot to seal the firewall but the CPP kit just seems like crap.

So my question is. Can I use my factory power booster and just put a disc master cylinder on it? i'm concerned about the bore and stroke needed to make everything work. Anybody done this?