Yes sir, starting in '96 the Y-pipe was ditched and each bank received its own pipe, which then went to a single muffler and tailpipe. You can get "true dual" exhaust by stacking two mufflers side by side, but this then creates an unequal flow due to the Bank 1 pipe being longer since it has to travel all the way to the passenger side because of the fuel tank. This is solved with an X or H pipe, or using a dual in/out muffler.
No hard feelings at all, its not that I value one thing over the other, I value whats best suited. Having a large displacement engine that does not rev high, a mild cam, long exhaust pipes, a heavy vehicle, and with the intention of being daily driven, my research pointed to large tube short headers. Ease of installation was moot, I had the front clip off and already planned to have the exhaust done from the headers back. I merely pointed out price and ease of installation because he is 4wd and did not specify his budget.
Unfortunately I do not have any solid numbers yet. Even when I do get around to dynoing Red, the gain will also be contributed to the other mods, so I will not know for sure what the headers did by themselves. However, I am planning a smallblock build very soon for a Tahoe, and intend on getting numbers after every mod, starting with headers. I have a pair of OBS shorties and a pair of Doug Thorley Tri-Y, though I think that is an unfair comparison. Even then, thats on a smallblock, big blocks are a different breed.