If you have an ignition key and cylinder that work you can re-key the door and spare tire locks to match the ignition key fairly easily.
Look in my build thread for an explanation of how to key the locks.
http://67-72chevytrucks.com/vboard/s...8&postcount=22
You can re-key locks or get fresh new locks with wafers to build. It's not as frightening as it sounds.
The door lock cylinders are in the door handles and the spare tire lock is in the end of the tube next to the license plate.
If you can find a decent ABS motor setup I'd install it. The ABS handles the brake bias similar to the combination valves on older rigs.
A 30 minute security learn is easy if your truck has security. Mine did not.
The FOBS are programmed separate from the keys. They're cheap. Just get the correct FOB Program it and go. The GM FOB that came with my 2005 K2500 is 15132197.
If you have fobs with deteriorated rubber and/or damaged plastic cases you can buy cases with rubber buttons and no circuit board for a little less than $7 to swap your OEM FOB board(s) into.