To each his own, I have experience no ill effects of drilling main jet one size bigger, same plug since I installed short block 4 years ago, maybe slightly more fuel, kind of hard to tell because I never really kept track before mod. Also the engine should run cooler with more fuel which leads to cdi failing, has original cdi. I did have a ping when motor was not loaded that drilling the idle jet cured. All's I know is I have a nasty hill to climb and my dura force climbs it with no signs of bogging just a nice hum. Both of my neighbors 4 strokers bog where they have to pretty much stop. The reason for the short block was I bought off a dealers pile that was sitting in the elements for several years. Rusted connecting rod bearing.