Carburetor - 750CFM Ultra Double Pumper

The HOLLEY Carburetor - 750 CFM Ultra Double Pumper Model 4150 (SKU HLY0-76750RD) is a high-capacity street and strip carburetor engineered for serious engine builders and hot rod enthusiasts seeking aggressive fuel delivery and responsive throttle control. The 750 CFM specification delivers substantial airflow for mid-range displacement engines while the dual-inlet design accommodates manifold port variations found in classic and modern street applications.

This 4-barrel square-bore carburetor features mechanical secondary activation with dual accelerator pumps—a configuration that provides linear fuel enrichment under load without the complexity of automatic or electronic secondary operation. The electric choke automates cold-start enrichment, eliminating manual lever adjustment and improving drivability in variable ambient conditions. Constructed from aluminum with red anodized and tumble-polished finish, the unit resists oxidation while delivering a distinctive appearance. Weighing 9.7 lbs and measuring 11.2 x 7.9 x 12.3 inches, it integrates into manifolds designed for square-bore carburetor mounting with standard flange geometry.

The 750 CFM platform targets engine displacements between 350 and 450 cubic inches, making it ideal for small-block and mid-sized big-block platforms in full-size street rods, resto-mods, and weekend strip runners. Buyers selecting this carburetor typically prioritize fuel delivery responsiveness over maximum lean-cruise economy—a valid trade-off in performance-oriented builds where throttle response and acceleration authority matter more than highway fuel efficiency.

HOLLEY carburetors remain the industry standard for street and racing applications, known for consistent tune-ability and part availability across decades of platform evolution. The dual-pump, mechanical-secondary configuration of this 750 CFM model sits between entry-level street carburetors and maximum-flow competition units, offering experienced tuners enough control to dial in mid-range drivability without sacrificing peak-load fuel delivery.