Also planning on doing a before and after dyno so I can see if there is anything to be gained by switching to a larger header. I know from research on the interweb that I probably wont gain much but every motor is different. The main reason I am upgrading is for longevity because Kooks is all 304 SS and BBK is, well, idk, the midpipe is aluminized steel and they don't say what their headers are made out of. However I have not had any issues with their 1-3/4" ceramic long tubes and would recommend them to anyone on a budget. Just don't use the o2 extensions on the front o2 sensors, many people have run into CELs or worse because of it.
2014 Mustang GT 6R80, Procharger Stage 2 D1SC, BBK 85mm TB, Boss IM, Sai Li fuel system. Circle D 3C, 1-7/8" Kooks Long Tubes w/Offroad X Pipe, Lethal Over-Axle Pipes, Corsa Quad Axle-Back, Eibach Pro System Plus, BMR K member, Shaftmasters DS, Forgestar CF-5 Wheels and Nitto NT05 tires. Lund Tuned
Lots of suspension goodies and some other stuff I can't remember.