I know what K and C mean, you said it has a K10 diff like you thought that is something special. Maybe that is my misinterpretation of why you said K10. I asked what the difference was between them, not what K and C means.
Also doesn't a cracked block cause water in cylinder and hydraulic lock? or water in the oil? What are the symptoms that make you think cracked cylinder.
Are you saying you want to keep the existing tranny or get a motor and keep it's 4L60 or 4L80? Those are mismatch to all the mounting of the motor and trans, mismatch to clutch, mismatch to driveshaft, mismatch to fan clearance, carb linkage, exhaust clearances, wiring...........fabrication, expense, headaches...
But I don't know what type of truck you see it becoming, how much time to do it, money and know-how.
Simple and good = wait for a motor. Don't forget to look at whole cars/trucks that are otherwise trashed with no title but run good. If you can't find that, there ain't a cow in Texas.
