1927 Chrysler Model 70 (closed car) Interior

Has anybody had this occur?

Cylinder head cracking.

Block is flat, head is flat, used sandwich head gaskets.

I have had this happen 3 times now.

Heads have been oven welded by Midwest Cylinder head.

Cracks are in the center fron side to side, in front of distributor or the rear of distributor.

Past 2 times it was leaking on the outside only.

This time #4 spark plug is much cleaner then the others, so I think I am getting fluid inside the cylinder.

Any reasons or solutions?

I would suspect it may not be flat or something is keeping the head from sitting flat.

Check to see if a stud or studs have some damage near the top of the block,

You could try placing the head on without the gasket or nuts and go around with a feeler gauge.

Another problem could be improper torquing or wrong torque sequence.

If it uses cap nuts (closed top) you could be bottoming on the cap before reaching the head. Is there enough thread on all the head studs to reach through the head, so you tighten down on the head and not the end of the thread?