if the truck has the mils it says it does from other thread you might want to look into injectors first, to many a good psd has been ruined from people stepping up performance with bad injectors.
DIY injector kit from rosewood diesel is a low cost way to do injectors.
They arn't selling DIY kit on their site right now. So call Jim (DZLJIM) and see if they have any or when. They do offer rebuilts for $500