Looking for rebuild advise

Hey Slant 6 fans. i recently decided to rebuild the engine in my 74 duster and i have a pretty low budget. around 500 bucks. now, i have lots of time to rebuild and want to build a Slant six that looks and sounds awesome, holds up well, and is responsive to the throttle. I plan on taking the ladyfriend for highway drives on the weekends, maybe entering the car in a parade or car show too. As far as performance goes, i love POWER but all those add ons get expensive. heres what i have so far...

2 Forged crank slant 6's 1974, 1976
(and all the stuff to go along with those)

A super-turbo muffler that sounds better the higher you rev the engine
(i was told not to rev a slant above 4500 but that seems high anyway)

basic air filter, oil filter, thermostat.

nothing special but any pointers anyone? thanks in advance.