From my own personal experience, way way back, I had a '67 Chevelle 283 V8 with "Hush Thrush" mufflers dual exhaust. The car had a great rumble until I installed full length tailpipes to the rear, then it was too quiet for my taste. Eventually, I installed that same engine in a 68 Chevy 1/2 ton pickup (The Green Machine). Headers, Hush Thrush, no tailpipes and it was exactly what I wanted.
I think Martin has the right idea. Make your best guesses and try a few different set ups.
Doing your own research, you may get it right on the first try.
Let us know how you make out.
John
