[Fred]

I am building a new motor for the Cobra. I have had head gasket problems and was going to increase from 7/16 to 1/2 bolts or studs.

What is the process to do this? If I place the block on my bench and tap the block for 1/2 bolts, the original diameter of the 7/16 threads is greater than the minor diameter for a 1/2 threads. The major and minor diameters do not work out. The thread depth will not be what it should be.

Am I to concerned about this?

Fred