y pipe to single in/single out or true duals?

[redz 1970 K5]

So I just got a sweet deal (on this forum) on some Hedman Headers for the K5.

My exhaust system has had it anyway, so now I am on the drawing board. The truck has a true dual system with stock manifolds and glasspacks now.

I have had late model trucks with dual 2 1/2" in and single 3" out, and I love the sound- low and mellow with a good balance.

I have heard though, if I use the right size pipe on a dual system with the right mufflers, the performance is better.
I was thinking 2 1/4" tubing with 40 Series Delta Flows.

I am slightly leaning towards a dual 2 1/2" in single 3" out with exit on the passenger side behind the wheel.

I know bigger isn't better, and in the past I have sacrificed low end for high end by going too large in pipe. Not any more.

What's your guys' take?