I have a 4mg77190 in a 379 Pete. The previous owner swapped it in there it's not the original engine which was supposed to be a 400hp. It was very underpowerd to pull 80k loads so I put a pump off of a 425 on it a few years back and also a turbo off a 400. It went from turning 1700 rpm no load to 2100 rpm no load. Also went from 17 lbs of boosts to 26. The truck ran great, no overheating and has never used any oil and only black smoked when going thru the gears until the boost got up enough to burn the fuel. Fuel mileage has allways been poor when loaded and even after changing the pump and turbo it still never performed loaded as well as the 425s I have driven. It burned a piston last week so I'm going to inframe it. What kit should I order to get the best pistons and also thinking of changing the injectors because I'm sure what's in there are pretty small it being a 310hp. Also should the timing be altered as well. Not looking for a hot rod but would like to go back with the right parts to get at least 425 hp out of her and 5mpg. Can anyone tell me the right pistons to use as well as what I need to do as far as injectors and timing? Thanks in advance. It's hard to find anyone around my area that knows b model cats.