Engine on a 67 john deere 2510 diesel overheated, died and seized. Tractor has cooled off and starter will only turn engine some and stop. Is it worth just removing and replacing pistons and liners and not pulling engine? I don't see any cracks on block and it has no leaks. I haven't investigated the overheating problem yet but that is probably easily fixable. The rest of the engine is my major concern.