Ive decided on my olds 403 build to go with dynomax ultraflo mufflers but now im still contemplating to go x or h pipe. From what I hear the H produces more torque and the x produces more top end hp. Is this true? I do love the sound of the H pipe over the X but this is a performance build and power is a priority thing. I know between the two I probably wouldn't notice the difference in power but theoretically which would be better for my engine? I have 10:2 compression and a roller cam in with lift in the 550's and duration in the upper 240's

 

Gear?

 

Either one with the addition of electric dumps!!!!! I personally don't think it will matter as much between the two! I think the size of tubing, routing, type of bends, and mufflers would effect your end result more!!

 

currently running 4:10 gears might drop to 3:73 later. I will probably just dump the exhaust right after or just before the axle. Im planning on using the dynomax ultraflo mufflers....