Milling 243 heads
 

Im sure this question has been beat to death and i looked an could not find the answer, but, what would be the most you would mill off the heads? would it be safe milling them say .042-.045''?

Thanks

The average most milled is 0.03 some people have milled them all the way to 0.05, but this can cause the intake manifold ports to not match up with the head ports. Also milling them more than 0.03 could cause strength/durability issues.

You could mill them 0.03 and throw a 0.03 or 0.04 head gasket on also, but modification to the intake manifold might have to be made in order for them to match up.