Zenymb 2" Phenolic Carburetor Spacer for 4‑Barrel Holley 4150/4160 — Open Plenum, Heat‑Resistant Insulation

This 2-inch open phenolic carburetor spacer from Zenymb sits between your 4-barrel carburetor and intake manifold to reduce heat soak and expand plenum volume for stronger throttle response.

Built from heat-resistant phenolic resin, this spacer is intended to keep carburetor temperatures lower while creating additional air volume in the intake tract. Its open plenum layout improves airflow at higher RPMs and the four-bolt square pattern fits most 4-barrel carbs, including Holley 4150/4160 family units. The package includes gaskets and mounting hardware so installation is straightforward for both home mechanics and professional tuners.

How does the spacer reduce heat transfer to the carburetor?

The phenolic material has low thermal conductivity, which limits the amount of engine heat that reaches the carburetor base. By maintaining a cooler carburetor, fuel remains denser and more consistent before entering the intake, helping preserve mixture stability under load.

• Constructed of high-grade phenolic resin for thermal insulation
• 2" thickness increases distance from hot intake surfaces
• Reduces heat soak that can cause vapor lock or lean signals

What performance gains should I expect on the street or strip?

The spacer enlarges the plenum and smooths airflow into the manifold, which can aid top-end power and throttle response, especially at higher engine speeds. Results vary with tuning and engine combination, but it's commonly used where improved high-RPM breathing and quicker throttle reaction are desired.

• Open plenum increases available air volume for high-RPM power
• 4-hole spread boosts mixture velocity for better midrange torque
• Works well with tuned intakes, aftermarket air cleaners, and performance carburetors

Will this spacer fit my carburetor and engine?

Zenymb designed this spacer to match standard square-bore 4-barrel bolt patterns, including common Holley 4150/4160 units and similar models from major manufacturers. It suits Small Block and Big Block Chevy installations and can be used with many Ford and Mopar setups when bolt and throat alignment match.

• Compatible with Holley 4150/4160 and many 4-barrel carbs (Edelbrock, Carter, Barry Grant)
• Fits standard square-bore bolt pattern used on SBC/BBC and many V8 intakes
• Includes gaskets and hardware for most conventional installations

How difficult is installation and what hardware is included?

Installation is typically straightforward and can be completed with basic hand tools. The spacer ships with the necessary gaskets and mounting studs or bolts to simplify fitment; however, verify thread type and stud length for your intake and carburetor to ensure proper clearance and sealing.

• Comes with matching gaskets to prevent leaks at the base
• Includes mounting hardware sized for typical 4-bolt carburetor setups
• Simple bolt-on design—no specialized machining required in most cases

Who this is for: Enthusiasts building or refining performance V8 engines who want a durable, heat-resistant spacer that improves airflow and helps keep fuel temperatures in check. It’s a solid upgrade for street machines, weekend racers, or anyone optimizing carbureted SBC/BBC engines using Holley-style 4-barrel carburetors who needs a reliable, easy-to-fit spacer.