Use the advice from the rod benders who went too far. Seems like over 600 hp and 4k rpm tears the top ends out I just put things at 500 hp and a nice EFI tow tune it does nice on egts and boost kicks up nice when you hit it. Stock tranny, Caltracs on rear diff. and EGR delete, AFE air filter, just putting out much more than stock and hope it is safe enough to hold together for a user truck with some street action that stays together the EFI tune doesn't smoke much so that might save fuel too. Just my set up to leave it there and use it. I will build an LS9 Camaro if I want to race I decided. Diesel is too expensive to fix and constantly try and resolve what is out of wack from last changes that were put in to run hell out of it for 12 sec. and clank what the hell has it done now. I can fix the gasser cheaper so it's what I will so now. These trucks cost too much to race and rip up and try to use it for work too. I need the work truck to last a long time. This is just our plan not to upset anyone in here with their total diesel head talk and rock.