ZZP 3800 Water Pump Underdrive Pulley

Dyno testing our 5.5" underdrive pulley on a near stock L36 showed 3WHP gained at 6k rpm. In car testing shows only a 2 deg increase in operating temps over stock. Higher gains are possible depending on your engine combination. Pulleys are available in a high gloss black anodized finish. 8% underdriven dyno proven horsepower lightweight design saves a pound of rotating mass increases water pump life expectancy better fuel economy One size larger than stock belt recommended. Does NOT fit HBody cars because of their front engine mount. Bonneville, Park Ave, & LaSabre.   Water pump pulley: 115 in/lbs.March 2025 update: New design to match our ZZP water pump pulleys from other markets. New weight is only 0.55lbs.