360 la headers & straight pipe

Your low PO 360 from truck van won't be that cool with no muffs
Be loud but not like a HP with compression and cam.
And the needs muffs for backpressure was covered on Engine Masters.
Headers with extensions was best. The formula was, painted a pipe and someplace at 16 to18 or 19 inches the paint burned off. That's where to end the pipe coming off the collectors
I think I would grab a bolt on from Summit set up if on the cheap. Or Pypes , or Flowmaster of ya like drone for street use.