Holley 4150 Aluminum ULTRA XP 650 CFM CIRCLE TRACK 57750BK the Hi-Tech belt drive system

the Hi-Tech belt drive system for Chevrolet Big Block reduces flap through the RPM range while absorbing crankshaft harmonics to prevent performance-robbing valve train instability

Double Adjustable for Ease of Installation

Does Not fit Convertibles

Two-Ten Series 1957-1955Vehicle Applications: Chevrolet Bel Air 1957-1955

XLO Ultimate

Holley 4150 Aluminum ULTRA XP 650 CFM CIRCLE TRACK 57750BK the Hi-Tech belt drive systemXtreme Performance Holley Ultra XP(TM) Circle Track Carburetors! Ultra XP carbs are 38% lighter than our original HP, have fuel capacity that is 20% greater and 30 other new features! They're available in our Hard Core Gray(TM) hard coat anodized finish with Black(TM) billet for improved corrosion protection & also available in natural tumble polished aluminum with Black(TM) metering blocks and base plate. The Aluminum Ultra XP Circle Tracks are