Right, isn't that what I thought I said you said? :D
I can't imagine there is going to be a huge difference in location between the TTI headers collector and any other brand. The driver side will be tucked up a little higher is all. Sure there will be some, but the first section of pipe can be rotated up or down to line up with the humps in the crossmember.
Once you have that whipped, the rest oughta be pretty straight forward.
Maybe if someone can post a pic of the TTI headers from the back looking forward, and another of the off brands that might help in comparison.