I have posted it before but, get into the 21st century, engine programs are out there that will calculate the proper advance curve for what ever engine combination you have with what ever fuel octane you have. Are they 100% accurate, no, but they are close, at least in my experience. I use performance trends engine analyzer. As with all programs you have to take the time to input good info, if you do, it hits not only HP and Torque, but things like idle vacuum, timing curve, cranking compression, fuel volume requirements, and much more. I never build an engine without running it through the program. I get a lot of people who bring me a pile of parts to build an engine with, the program helps figure out if its a combination that will work, and helps convince them if it won't. Plus the program is a lot cheaper than a burnt piston, and fun to play with on a rainy day.