Well I have been scarce around here for a few months cause school has been beating me down but its time for some motor building action. The 6.2 I had in my trail truck died rather disappointingly in the mud pits during the summer. The motor never ran very well, I got it for free and never too the heads or anything off. Well it turned out to have three cracked pistons, and I think the injection pump and/or injectors finally wore out or broke too which caused its final death. So I got a whole new (to me) motor to rebuild and thats where I'm at now. The rebuilder is sourced from a CUCV so its probably an 84. It was prety rusty on the outside but once I got it torn apart the inside was great looking except one cylinder had some water and rust in it from sitting outside. We got the block all cleaned up and I ordered a ring, bearing and gasket kit with standard bore rings. My friend that is helping me build the motor was checking the ring gap and said that it was too big, indicating worn cylinder walls and that I would probably need to get the block bored out. I was hoping to avoid this because of the added expense but the block is at the machine shop getting checked out right now. Now I am expecting the machine shop to confirm my friend's opinion that it needs to be bored out, which means I am going to have to get new pistons, which means I am going to have to re-balance the rotating assembly. My friend told me that once we get the pistons we can put them on the rods, and then ballance the rotating assembly ourselves. I am not familiar with this kinda stuff at all but he seems to know what hes doing. He said that the crank is already balanced by itself so all we need to do is put the pistons on the rods, weigh them, find the lightest one, and then grind off the skirt of the rods until the heavier ones match the lightest one. Is this all as easy as it sounds and a credible and reliable way of doing it? I would love to save the $175 the shop charges but not at the risk of destroying my motor with killer vibrations. I am just sticking an old set of heads on there for now and re-using the factory head bolts. I know this is a typical no-no but I seriously cannot afford to get new bolts or rebuild the heads right now so the plan is once I pay off the bottom end rebuild I will rebuild a set of heads and install them with new bolts. I am having the injection pump and injectors rebuilt by accurate diesel, since everyone seems to like them so well. I was wondering though, has anyone given any thought to raising the governor limit on a 6.2? From what I have heard the governor is in the injection pump and I have read a few articles about 6.2's mod'd to run 5-5500 rpm. I know the factory redline is 3600, would it be safe to have it bumped up to 4000 with a bone stock bottom end? I just want a little more horsepower for playin in the mud and making lots of noise. Thanks for the help, here's some pics. What killed it Cracked piston 1 Cracked piston 2 Cracked piston 3 And the new block all cleaned up and ready to go.