OK I just bought my Afr 165 heads and need to get a head gasket. I am confused becouse I have a 4.030 bore. Most all the gaskets, the bore sizes are 4.100. Now will this hurt my engine or make the gasket weaker by running the head gasket bore bigger then my engine bore?
The 4.100 is a standard size and is what you need, you need some clearance around the bore. Personally I would suggest a Fel-Pro 1011-1 for your set-up.