I have an early 60s 530ck with a 188 diesel. I'm doing an in frame rebuild as it's froze up. The cylinder seals were leaking and number 2 and 3 cylinders were cracked. I need to rotate the engine to pull the rod caps but I can't seem to free up 2 and 3 pistons. I've tried blunt force, heat and soaking with pb blaster. Machine rolls in neutral so I know I'm not fighting the transmission. Anyone have some thoughts or ideas on this.