PQY LS Coolant Crossover Steam Vent Kit 4-Port — Stainless Tube & Anodized Aluminum, Fits 6.0/5.3 LS Engines

The PQY LS Coolant Crossover Steam Vent Kit is a 4-port stainless and aluminum steam relief line system engineered to route pressure and steam away from LS-series intakes for safer cooling-system operation.

If your LS1/LS2/LS3/LS6/LS7/LS9/LSX engine setup lacks a clear steam path under the intake, this PQY kit supplies a compact crossover manifold solution built from 304 stainless tube and anodized aluminum connectors. It replaces cramped factory plumbing and gives the radiator cap a reliable way to vent excess pressure, helping prevent trapped steam pockets in the crossover area. The set ships with manifold pieces, couplers, end fittings and lag hardware for a near-complete installation.

How does the PQY LS steam vent kit prevent steam buildup?

This kit creates dedicated vent lines that allow pressure and steam to escape to the radiator cap as intended rather than becoming trapped inside the crossover. The stainless tubing and tapered-thread fittings minimize leaks and help maintain a sealed system while providing controlled venting points. Proper routing reduces hot spots and makes coolant circulation more predictable under load.

• 304 stainless steel tubing resists corrosion and holds shape under heat.
• Tapered-thread aluminum fittings reduce leak risk; thread sealant recommended.
• Four-port manifold layout vents multiple crossover locations simultaneously.
• Pre-cut couplers and end fittings simplify assembly and connection to radiator neck.

What engines and configurations are compatible with this 4-port kit?

The PQY kit is made to be universal across many GM LS-family intakes — including LS1, LS2, LS3, LS6, LS7, LS9 and LSX engines — but compatibility depends on your intake’s clearance and existing plumbing. It is especially useful where traditional hard-line crossover runs cannot be routed under the intake. Measure existing port spacing and verify thread sizes before purchase to ensure fitment.

• Designed for LS-series engines with limited under-intake clearance.
• Works as a retrofit replacement for many 5.3 and 6.0 steam vent setups.
• Universal fittings allow trimming and orientation changes during installation.
• Check manifold spacing and thread pitch against your engine ports first.

What comes in the box and what tools will I need to install it?

The kit ships with multiple manifold pieces, corner ports, couplers, end fittings and lag spikes to fasten the assembly. Typical home-garage tool needs include basic hand tools, pliers, a thread sealant or tape, and possibly a hacksaw or tubing cutter if you need to shorten tubes. Always install when the engine is cold to avoid exposure to hot coolant or steam.

• Included: 5 center manifolds, 1 corner manifold, 4 couplers, 9 end fittings, 4 lag spikes.
• Tools: hand wrenches, thread sealant/tape, tubing cutter or hacksaw for length adjustments.
• Safety: install only on a cooled engine to prevent burns from hot fluids.
• Tip: test-fit components before final tightening to confirm alignment.

How durable and leak-resistant is this steam port kit?

The PQY kit combines 304 stainless tubing and aluminum fittings with tapered threads to reduce leakage and withstand the thermal cycling common in performance engines. While the materials are corrosion-resistant, correct installation practices such as using a thread sealant and proper torque on fittings ensure the best long-term reliability. Regular inspection after initial fitment is recommended.

• 304 stainless tubing for strength and corrosion resistance.
• Tapered-thread aluminum fittings designed to seat tightly.
• Use thread sealant for added leak protection in high-heat areas.
• Periodic checks advised after the first few heat cycles.

Who this is for: The PQY LS Coolant Crossover Steam Vent Kit suits enthusiasts upgrading or repairing cooling plumbing on LS-family engines where intake clearance prevents standard hard-line routing. It’s aimed at DIY mechanics, street-performance builders, and racers who need a compact, serviceable vent solution with durable materials. If you want a direct replacement for cramped or leaking steam ports on 5.3/6.0 LS setups or need an adaptable manifold for custom plumbing, this kit provides the core parts and flexibility to route steam away from the intake safely.