I have these headers

http://store.summitracing.com/partde...3&autoview=sku

on my 310. They have a 2 1/2 collector. I am getting a dual setup in the next few days and I wanted a recommendation about what setup to go with.

Should I go dual 2 1/2 back, or dual 3 back? X-pipe or H-pipe? I was searching and only found one thread on x vs h. X = more HP, H = more TQ and there is a sound difference.

My goal for this car was to get it to a point that I could drop in (almost) any motor and go. I have done that so far, just need exhaust. I plan to put in a 400 SBC in next few years. Should I just get 2 1/2 back and change later with the motor?

As far as x vs h, which would work best on my 310 with those headers? why does an X produce more HP while an H produces more TQ?

The exhaust is going to be custom done btw. The shop I'm going to can only do crush bending, not mandrel bending.

Thanks, I hope I gave enough info.

Edit: I was thinking of these mufflers

http://store.summitracing.com/partde...8&autoview=sku

or the 3" version.