Modified & Tested 1850 Vac2nd 600 CFM Single Feed/Pump to 4150 Dual Meter Blocks

Listed as "Used" but I personally refreshed & customized/modified this vintage 4V into a high performance working carb. Nothing fancy as Holley also offers a kit to convert it. This carb is no longer equipped with all original parts. Photos were taken in various incandescent, sun, and natural light conditions. This Custom Vintage Holley 4V 600 CFM High Performance Carb, is now a 4150 Model Series, with Dual Metering Blocks, originated from a 4160 Series List 1850 core, vacuum secondary, single feed & pumper. This 4160 1850 carb, dated 0654, built in March 1974, was converted to 4150 series by removing #9 secondary plate assembly and installing a secondary metering block with jets but no power valve. Bought as a core project without the baseplate so installed a good 1850-2 baseplate for PCV, newer 109 & reconditioned 118 throttle plates. New parts: - Choke (Electric). - Primary Pump Diaphragm. - Primary #65 Jets. . Power Valve #2.5. - Good Secondary Diaphragm and #75 Jets.     . Universal Primary Throttle Shaft        with Ford kick down heavy duty        spring. - Resealed Secondary Shaft with Holley PTFE Ribbons. . Needle Seats QF Viton 110. . Banjo Swivel Inlet Connector. - Good Non Stick Gaskets & O-rings. - Longer Transfer Tube & Screws for secondary. Now it's modified, kinda different or same as others have done, but an affordable performance carb. Fair original plating with patina. Has original fuel bowls, main body, secondary pod, and primary metering block. I have the original #9 secondary plate assembly if you wish to have it when purchasing. Ultrasonic & hand washed, & rinsed with vinegar. After video was taken, soda blasted air horn area, venturi runners, & barrels. Most original plating remains. I've tried to pin clean and dry every passage with an air compressor. March 2026 Tested on a SBC. Swapped out needles/seats, power valve, & primary metering block. Floats, primary accelerator pump/nozzle, & venturis all work. Secondary diaphragm opens throttle blades with WOT. Video shows it roaring like a lion. On cold, it started quickly. Choke closed and opened as designed. Idles at low rpm. Air fuel screws adjusted at low rpm. Vacuum pulling from front meter block. Now everything works as designed. It is ready to bolt onto your motor. Carb adjusted to my wet motor settings: float levels, air fuel screws, idle, choke cold fast idle, accelerator pump arm spring screw, secondary idle screw is frozen, and choke thermostat. Thx for looking.

• Brand: Holley
• Choke Type: Electric
• Type: Carburetor
• Mounting Flange Type: Square Bore
• Features: Down Draft
• Material: Alloy, Aluminum
• Barrel Count: 4
• Vintage Part: Yes
• Country of Origin: United States
• Performance Part: Yes