Brake Booster/Master Cylinder for 1-ton, disc conversion - Suggestions?

[suprachrgd82]

I'm looking for some product guidance here. There's brake master cylinder/booster assemblies available everywhere for 3/4 and 1/2 ton trucks, but not much found for 1-ton. I think clearance of tall valve covers limits me to stock/existing booster size.

I am looking for a complete assembly with proportioner.
Could you experienced folks point me towards one?

Truck details, to the best of my knowledge:
'70 Longhorn, 1-ton, single rear wheel
Bolt in disc conversion from another year Chev truck (4-wheel disc)
BBC 400, "Custom Camper 30"
Tall valve covers
Don't carry a camper or loads above 800lbs

The existing MC is partially visible in the pic. It's leaking like its made of swiss cheese. Don't want to rebuild; new ones aren't that expensive.