Drove the K20 to the exhaust shop, American Muffler, and they are doing their magic as we speak. Truck is running pretty rough, back firing or missing so I've got a problem to figure out. Not good as I know nothing about motors. I was sweating driving it as I could just see getting stranded. Stayed up last night til 1 am getting the passenger door guts installed and getting both doors to latch shut. Figured that would be handy not having the doors fly open driving down the road. Can't wait to hear how the exhaust sounds. The system is planned to be 3" from the headers to the x-pipe, then 2 1/2" to Dynomax UltraFlo's and continues as 2 1/2" pipe dumping at the rear of the flatbed angled down slightly.