Getting Noss cool head installed.what size domes should I use.Stock motor,adjustable timing plate +4,FmF fatty gold pipes,13t sprocket.I would like to still use pump gas.What compression should I stay under?Also do you think that that it is benificial to change my mix ratio from 36:1 to 40:1.I have been running 36 to keep my old 1993 motor lubed,but i heard that running 40 will yield more hp.36 or 40?