All Hudson heads measure 2 inches front to rear. Cast iron heads can be milled .080 thousands. Aluminum heads can only be milled .050 as the head chamber is smaller. Then you have to keep an eye on the left side, driver, for leakage from 3 and 4 cylinders. Even when new they leaked. Find a good cast iron and keep it at 1inch nine twenty. Walt.

Moved to the "Hudson" forum category.

I have had no problem with aluminum heads using a BEST Perm Bond Gasket with 7/16 or 1/2" Studs[size=4][b][b][b][/b][/b][/b][/size]

I also have had the Aluminum heads develop a pin size leak over the top of the pistons and drip antifreeze right on top of the piston. I don't trust them and took mine to the salvage yard and sold them.