Different strokes for different folks.
My 63.5 with a 390 stroker, I welded up mandrel bent 2.5 inch exhaust.
Easy to fit, easy to install, and I think at street rpms under 5,000 I don't think I'm losing anything.
I have cutouts at the headers for track usage should I so choose.
For mufflers I bought the cheapest ones I could find. Summmit turbo mufflers. I think they were $18 each.
have an idle and accelerating video.