JoeH,
I am about to build a 250 with the same cam you have, so I am trying to make some predictions about how it will run. Can you fill in a few details about your 37?
Exhaust - iron [which one?] or headers [which ones]
Intake - Offy 3x1v? Other?
Carbs - which ones / venturi size?
Exhaust - single or dual, pipe size & muffs?
Rest of engine, stock 250 or just .030 over or etc?
Much thanks