i have a 00 cummins auto,with edge hot comp box, banks high ram, k&n cold air, 125 injectors, holley blue with big line, tci convertor, and a really pegged out egt gauge. what size of turbo should i get to lower egts and what else would help? i run about 37 psi

 

At 37 psi you are pumping hot air into the engine....should back it down to 30. I'd say a HTB2 62/12 or 62/14 would work great for you.