I have a 2000 gmc 1500. I currently have hydroboost brakes and its done nothing but cause me headaches from day 1.. I have had 3 cars with manual brakes and they all stopped better then this setup but those cars were all manual brake kits. Bought and bolted on..

what bore master cylinder is needed or which master cylinder is everyone using and what adapter plate you guys using?

 

I hate to be " That Guy".... but...
You are clearly mistaken. Hydro-Boost is the good stuff.
If you are driving on public ROADS, you want and need a functioning brake booster.

 

Manual brakes suck, fix what you got.