Both cylinder heads have very similar cracks (one in each head, from spark plug threads to intake valve seat. They are hard to see, can't leak anywhere, but question is can these heads be used?
I am by no means an expert on the topic but in the few years i've been working on cars i make it a point to never use stuff that's cracked. NOW! having said that... you could probably us them and they might run but i wouldnt use them if you have any dreams of high performance or high compression/boosting the engine. Only God knows what could happen under load the head might flex causing the valve to sieze in the guide and wiping the cam, or causing the valve to break off in the cylinder and punching holes in the top of the piston (i speak from experience here :roll: ). I just wouldn't use em too much at risk cuz it could cause a lot of damage. By all means if i'm wrong people please chime in and set both of us straight.
I would not use them. The crack will get worse and the seat will end up falling out. This would cause massive devistation. Nice pics to use to show what detination does to the head. Looks like craters on the moon.
