Yes sir you are correct it is .040. I had read a thicker head gasket didn’t lower compression as much as I would think. I’m not 100 percent as I only read it. And I thought a head gasket being thicker may make it easier to push out? Like I said I’m not a engine builder, I did build mine but may have gotten lucky with my results. The combination I think performs well I had just recently pushed the head gasket out and it made me think about switching to a aluminum head while I was that far. I was just kinda wondering about the 68cc helping me from the 62cc. I have been running this engine for several years but really only put maybe 100 miles a summer as I don’t have much time to take it out and actually drive it. I can change to a better head gasket and and check the tune again like RumbleFish said and maybe a higher cc head may help? I read aluminum heads can help with compression as well. That’s also the other reason I was thinking about swapping the iron heads to aluminum. Thank you.