Something as simple as a Y-pipe connector kit that ended in a T4 garret flange would go a long way.

I toyed with putting dual EVO16Gs that would be mounted right off a 3" header flange to evo flange adapter that would have been easy to fit on my Rocky, or a D series pick-up.

EVO16G's are cheap and easy to port on the hot side, 2 of them would easily support 650-700 horsepower on a 5.5 liter pushrod motor at 6500RPM.