Sea-Doo › Sea-Doo 1503 4-Tec Top End Rebuild Kit (.5mm Over) Image 1 of 1 Sea-Doo 1503 4-Tec Top End Rebuild Kit (.5mm Over) $745.71 Premium rebuild kit for mid-generation 4-Tec engines requiring minor overbore correction. Add To Cart Added! Premium rebuild kit for mid-generation 4-Tec engines requiring minor overbore correction. You Might Also Like Sea-Doo 900 Top End Rebuild Kit (1mm Over, 75mm) $565.43 Sea-Doo 580 Top End Rebuild Kit (.25mm Over Platinum, 76.25mm 1992-1996) $197.38 Sea-Doo 900 Top End Rebuild Kit (Standard 74mm) $565.43 Sea-Doo 580 Top End Rebuild Kit (1mm Over, 77mm) $238.56 Sea-Doo 900 Top End Rebuild Kit (.25mm Over, 74.25mm) $565.43