Header Size Recommendation

I have a 74 Dart Sport (that I'm cloning into an early Duster). I have the following from a D150 that I bought for parts:
-360, 11.2:1 actual compression, 292,.508 Mopar cam, ported heads w/ 2.02 intakes and 1.60 exhausts (I don't remember the casting number, they're in storage right now.), Torker II and 750 Vac sec. Holley.
-727 W/unknown stall convertor. It was about 3500 if I recall, when I test drove it before I took it apart.
-4.10 gears
Car will probably weigh around 3200 w/ me in it.

I need opinions on the header diameter required. I suppose the length too, if it's possible to be picky. It'll have a dumped exhaust (street car).