I can not answer for certain about big john setup but his photos looks like a disc/drum set up since he has a proportional valve. Mine will not have the proportional valve because my set up will be drum/drum. I will make an access through the floor to check the fluid. The good news is i installed the bracket today and after the powder coating the frame i will install the booster, mc and brake lines.
"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my sweet ride." -Amen
56 Chevy 3100 
