how much power...

Looking at new trucks and might go for a duramax this time. I have a brother that can get a good price for me on a duramax, was planning on keeping this one to custom tune, intake and exhaust for reliabilitys sake as my 6.0 has not been exactly reliable with injectors, turbo and such even after egr delete, studs... honestly between this and a 6.4 powerstroke. how much power you guys making with ppe or efi tuning alone?