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.