i was curious if a x/h pipe is still considered true dual exhaust? and whats the purpose of it compared to a seperate pipe going down each side of the block?

 

The H or X pipes are used to equalize the back pressure on each side of the exhaust. The firing order of the small block Chevy is configured so that two cylinders on each bank fire one after the other: 8 & 4 on the right side and 5 & 7 on the left. When this takes place there is a momentary increase in back pressure on side and a momentary decrease on the other. The H pipe allows the pressure from the high side to go to the low side.