408 with tti's. Do I go with H or X pipe exhaust

I have a 3" X-pipe and Dynomax Ultra Flo mufflers ending at the rear end housing of my 360 Dart Sport race car. I had to do a little trimming, fitting & twisting of the pipe angles, but it works great. The X-pipe joint is directly under the end of the trans tailshaft housing. I may have had to put a little dent somewhere on top of the X to insure clearance. I don't think you'll have much room to move it around. But every indication is that it has helped performance over open headers. So I kept the system on and removed the 60 lbs of weight it all added from other areas of the car to maintain my minimum race weight.

I have to drop the system from the collectors on back to change the transmission. But it's just the 6 collector bolts and 2 hangers above the rear end housing.

As for scavenging, I believe that an X-pipe is more effective in that respect and also makes more HP than an H-pipe. Unfortunately I don't have any direct info or other data to support the scavenging belief. But a vac-u-pan system works best with the tubes at a 45* angle (X) to create a vacuum & scavenge the crankcase as opposed to a 90* angle (H), and I'm running my carb leaner than I ever had before. I'm under the impression that each side of the "X" helps scavenge the other side as the exhaust pulses alternate from side-to-side. But I'd be interested in hearing about other opinions/theories.