I'd thought about swapping the gears and have sent an e off to PATRICKS for further information.

When you say a three speed OD Chevy trans do you mean the POWERGLIDE 3.55 tranny from a 50 -54 chevy car?
I've read the tech articles on the T-5 swap and am clear that I lack the skill and fortitude to pursue that angle.

I've got a line on the Holley 390 and am waiting for it to arrive, before I go off ordering an intake manifold.