+1 to
@318willrun suggestions.
i'd recommend a throwing in a 360 2bbl cam (or something similar) while you're there-- you can have yours re-ground and the lifters refaced.
but beyond a good timing set, fresh oil pump (and pick up!), hardened exhaust seats and having the heads gone thru it's hard to say what else you might be looking at until you get the motor open.
hope for minimal wear and you can get away with a re-ring-- the early motors already had decent compression. but if you need to go next over, there's tons of options piston wise for what you're trying to do. how spicy you wanna get (*cough* lighter pistons *pistons*) really depends on budget.
ETA: on the duals, get with TTI. they sell a complete kit from head pipes to exhaust tips and the fit is absolutely spot on.