True dual exhaust, IMO, doesn't need the "H" or "X" cross over pipes.
I don't know of any advantage to using them. [sm=insomnia.gif]
There must be some reason.

I like the true dual exhaust, 'cause I can listen to, and see, what's goin' on with each bank of the engine.

 

It's a pressure thing. The X or H pipe helps to even out the back pressure. I noticed a change on my truck when I redid it with identical runs. If the pipes are bent in identical runs and constructed of the right size pipe,(not too small, not too big), than I can't see any reason to having either. I think they are more useful on systems with asemetrical bends,like on a 4x4, etc., where the pipes have to be routed differently.The vette allows for semetrical runs under or along side the car so like I said I don't see any reason for them,......but I'm no expert. Maybe you could PM Mech259, I would value his opinion. Too bad Lee Willis is nolonger a member, he would have an answer as well. Cheers

 

I can see the value of balance to the length of the two pipes. My '80 would have to have the "X" pipe, due to the single cross member pass through is to the passenger side.

 

I haven't had any vehicle with a cross-over but the way I understand it the exhaust pulses from one bank help scavenge the other bank through the cross-over, even with equal length duals it is supposed to have some benefit.

 

FlowMaster makes an alum set up to replace your stock one.
I have stock 2" on my 74 but am going with 2 1/2" soon

 

I think 78buckshot hit it on the head. I also remember reading where to properly position where to put the "H" pipe, you need to put temp sensitive paint on the exhaust pipe. This is where it gets a little foggy (destroyed too many brain cells in college and the Navy [sm=icon_guiness.gif]) but you either put it at the hot spot or cold spot.

 

Will exhaust shops take the cats off to make it true exhaust?