I have a DC 4-1 ITR header (2.5" collector) plus cash on my part - lmk
If what he has Jeremy is the true DC ITR replica, then they make good power. It leaned my tuned ITR motor out some from changing from my ITR header with a collector mod. Flows really good.
I'm currently rocking this header on my car untill I get a nice repelica for the daily.