Ok, specs from my '65 FSM.
Posted by:
beemrmax
(69.41.139.---)
Posts: 275
Date: August 25, 2009 12:03PM
Brake Master Cyl Bore;
D100 1.00
W/P/D200-W100 1.125
D/P300 1.25
W/WM300 1.25
All 500-600 trucks 1.50
Clutch Master Cylinder bore is 1.125 from a D100 to a D700 and the slave bore is 1" for all as well.