Here are the photos,hope they help.
https://flic.kr/p/2jKaVMX
https://flic.kr/p/2jKaVyv

On the original GMC 248, have 2 stuck pistons. removed the crank. Other pistons came out nicely. Just the # 2 and 5 piston really in there. Used a block of wood and hammer, still no avail. Now soaking with more fluids. Fun, Fun, Fun...