Need a plan - component selection for restoring 68 340 that runs on 91 oct

The sound was mostly in the rectangular tips, the small diameter pipes,and the overlap.
But you can't reproduce the sound unless you have the same tips and pipes, and that kindoff limits your power potential, cuz the pipes were skinny-azz pipes. And it is those skinny pipes which hustled the exhaust to the back, and put the power into the tips.
Another reason for a stock-rebuild.......... I guess,lol.