Two Norton Ultra Hi compression domed pistons for racing fuel only 750 to 850cc
These domed pistons to give you approx 11.3:1 C.R. for 750cc long strokes and 750 shortstrokes (more info). 73mm = 185 grams. 77mm = 210 grams. A drop in kit with no modifications except that bores greater than 78.5mm will need larger diameter combustion chambers. Includes rings & .708″ DLC pins. Must be combined with our longer rods. Not recommended for 850s and up unless using alcohol (approx 12.5 to 13:1 C.R.). Will work for gasoline 850s with combustion chambers larger than 51cc (approx 12:1 C.R.). Crank rebalancing is not required (balancing info).