Building out a 273 recommendations

I'll agree with the rear gears, my Valiant IIRC had 2:56 gears in it. with the 225 the gas pedal was used as a on off switch. 3:23 would be a minimum for ya.

You could also step up to some 318 heads although you wouldn't be able to use your existing intake, use softer cam, The TTI exhaust with Duals will run 1400.00 alone, not sure if that's where you want to spend your money.