Great pics.
They could be up a little bit more, but they did a nice job, esp compare to the crap that is out there....
The Tri-Y design is one reason they clear more components (overall less tubing and no area where all 4 tubes come together). I thought I recalled that a Tri-Y design also helps torque, but my 'old memory' isn't as trustworthy any more..
.. so I consulted google and found a Hot Rod Mag article on 'selecting the right header', and the pros of Tri Y headers are listed as: "Tri-Y Long-Tube: Tri-Y headers came to popularity when they were used by Shelby for the GT350 Mustangs. The tri-Y design combines a short primary that is paired with another cylinder that is synchronized in the firing order into a 2-into-1 collector that steps to a larger diameter secondary tube. The two secondary tubes are then merged into a final 2-into-1 collector creating an overall length similar to a 4-into-1 design. The traditional design works well to build more torque from idle to 4,500-5,000 rpm, so they are very effective for street use, however, autocrossers and road racers also love them for their midrange torque and increased throttle response as well. NASCAR teams use a derivative design, called a 4-into-2-into-1 (4:2:1), which uses much longer primary and secondary tubes for higher-rpm effectiveness."
Full article here:
http://www.hotrod.com/articles/how-to-pick-the-right-header/