Earl's leads the way with firsts for LS engines! Water pumps come with push-on barbs for clamping the standard radiator hose. Push-on hose connects just aren’t good enough for the hard core performance minded. Earl's offers an adapter kit to convert inlet and outlet to -20 AN. One kits works with ALL LS water pumps. Included is an O-ring adapter plate which upgrades early LS water pumps to the later, less restrictive style of thermostat.