i have a friend that wants more power out of a 94 3500 5 speed CTD,we already have an Hd clutch,guages, the TST torque plate,4" exhaust, ,and this truck put down 260 hp,630 ft lbs with just this. I'm thinking the next mods should be 370's,and a GSK,does this sound right?,Im wondering how much Hp we should gain,and do we need new delivery valve?We want to get the most we can without changing the turbo,this truck does no towing either. Thanks in advance.