Just joined cumminsforum. Have a 98 12valve for 4 or 5 years but havn't done anything with it yet. Just bought a 6.7 3500 to pull my trailer with so now I'm looking at building my 12 valve for some speed. Anyone know of any good diesel performance shops in Phoenix? I need some guidance for where to begin with the 12 valve. I also want to get my parts from someone local that I can talk to. I tend to learn a lot more that way compared to buying stuff on the internet.