I hope i never have to replace headers on any vehicle again! It turned out that both of my OEM manifolds were cracked, so i needed to do this anyhow.
I installed the DT headers and a Nismo catback, i finished it last night. The SES light came on, but I am assuming that is due to the elimination of the primary cats. I'll get the code pulled today. It runs and sounds great! I'll post sound clips soon. There is no degradation of performance from the s/c, before i had only 2 lbs of boost max, it seems to be back to normal now.
To everyone worried about the backpressure issues, can a more open header really be that less restrictive than a manifold that is almost cracked in half?
Anyhow, I just wanted to post that it does work, and i will never do it again. It's not that hard, but it is a PITA to get in there, there is no room.
A few notes:
The Driver side comes with 2 02 mounting locations, but the secondary cat has the factory location of the second o2, so i just plugged the second opening in the header.
jack up the truck, i dont have a lift, but i jacked up the front and took off the front wheels. When you remove the rubber fender liners, you can get to 90% of the bolts you need.
You can only reuse half of the factory studs. The OEM manifolds use 3 short and 3 long studs into the block, the long ones are too long, so we bought 6 more short from a nissan dealer for about $2 each.
There are 2-3 bolts on each side that are impossible to get a socket on the DT headers, the pipe goes directly in front of the mounting hole and the stud is just long enough to block getting a socket on them, unless i missed something.
Other than that, it went ok, just took forever. I didn't worry about a how-to because i was following other people's how-tos and it was pretty much the same. I did pull and install most of the parts through the wheel well rather than through the engine bay though.