Thanks guys. It seems these Darton sleeves could help with the overall sleeve integrity of a highly tuned motor, not to mention the possibility of increased cooling efficiency. Even if these results were small, every little bit counts. I don't plan on dealing with turbo, maybe a supercharger. I'm leaning more towards a n/a motor with high compression, vtec, additional headwork with lightweight, balanced internals. I'm just developing a direction to work towards for now, details will show themselves along the journey.