The ESP High Rev Pistons have expanded and improved for 2018. They are now made for 34mm, 36mm and 38mm diameter pistons, (light weight available for the 34mm and 36mm pistons), and the sacrifice of compression is now very very small, (less than the difference of a .002“ thick cylinder gasket). For sale at DDM, we offer the exhaust duration increased by 5.5 degrees. I have cut the intake skirt for more intake duration for some 36mm pistons, but I think I will leave the intake skirt stock from now on for retail. They are great for stock and modified engines, and will rev higher if the pipe lets the engine rev. But for you guys who build your own engines, and may want maximum duration, call me. I can custom cut your pistons up to 7.5 degrees on the exhaust, and what ever you may want on the intake, saving you cylinder porting time and the cost of different cylinders. If you must have high rpm power, you should not overlook these pistons.