If you start your engine and it doesnt knock from the oil pan then your rotating assembly could have been spared. It definitely blew the head gasket(s) being it was so hot. The heads will warp and the combustion will blow holes in the head gasket. You would need the heads re surfaced or replaced. There are oil passages and coolant passages in the block. Oil for the cams and lifters and coolant for well, cooling. You can definitely burn oil due to a failed head gasket if the passages are exposed. Typically it will burn coolant or leak coolant out of the block. Severe overheating can definitely ruin your rings and ring lands causing blow by as well as burning oil. Drain the oil and check for metal bits or dust; remove the oil filter and cut it open. Your coolant will have metalic like stuff in it, thats your head gasket. Lots of times it is cheaper and easier to buy a new engine. Being to rebuild one yourself youre removing it out of the vehicle anyway. If your oil doesnt have metal in it could just be the head gasket. Once one head is pulled youll know if your pistons are gone. Good luck!