Brakes always had a fair travel and needed a lot of force to haul the car up. The brake system couldn't lock the wheels and so the engineer wanted to see something better.
The disc brake conversion came with 1" bore master and 9" dia single diaphragm booster.
Swapped the booster for a dual diaphragm 8"... no dice.
Ended up going for a 1 1/8" bore master to reduce the stroke and a Hydro-boost brake booster to give the extra "oomph" required...
Made up high pressure hoses using Speedflow AN-6 fittings and Speedflow high pressure power steering hose...
Installed...
Wow! Chalk and cheese!
Standing on the brakes will lock all four tyres now. It has transformed the car and the engineer is well happy.
For anyone going to 4-wheel discs on an Amercian full-size, don't muck around with vacuum boosters... go with a Hydro-boost unit.
JRD