Vacuum Port Cap Plug Plate LS SC Blower 551383 For LSA LS9 LT4

Vacuum Port Cap Plug Plate

This vacuum port cap plug plate seals off unused ports on supercharged intake manifolds of LSA, LS9, and LT4 engines, referencing part number 551383.

Overview

This heavy-duty vacuum port cap plug plate is engineered to block off the rear vacuum port on high-performance supercharged engines. Built for customized builds and custom supercharger swaps, this block-off plate prevents unmetered air leaks. This vacuum port cap plug plate helps maintain stable boost pressure and smooth engine idling.

Built For Performance

• CNC-machined from lightweight aluminum for strength and longevity
• Anodized finish prevents corrosion and wear under high-heat conditions
• Includes a premium rubber seal to ensure a leak-free fit
• Precision-drilled mounting holes allow a direct bolt-on installation

Fits These Machines

• for LSA Engine
• for LS9 Engine
• for LT4 Engine

On-The-Job Use

• Plugging the bypass vacuum port on custom supercharger engine swaps
• Preventing boost leaks that can lead to engine power loss
• Neatening engine bays by deleting unnecessary vacuum lines

Specs At A Glance

Good To Know

Q: Does this plate include mounting hardware? A: Please reuse your original factory bolts or source compatible replacement screws for installation, as hardware is not included.

Q: Why is sealing the supercharger vacuum port important? A: Any unsealed vacuum port allows unmetered air into the engine, causing lean fuel mixtures and rough idling.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.