Part #2610 has been discontinued in favor of INTAKE VALVE & COMBUSTION CHAMBER CLEANER (part #2611), which is a more modern version of 2610 all the way around. We updated the formula to include several different active ingredients and we changed the delivery system to make it easier than ever to apply. In the same regard, part #2630 has been discontinued in favor of BERRYMAN 4-STEP PROFESSIONAL AIR & FUEL SYSTEM MAINTENANCE KIT (part #2640). Both of these newer products are GDI compatible.