1987–2006 Jeep Wrangler YJ/TJ | LS Swap | 3-Row Polished Aluminum Radiator

The LS Swap Is the Modern Answer to the Old Question. Make Sure the Cooling System Keeps Pace.

The GM LS engine family has become the dominant V8 swap choice for YJ and TJ builders over the past two decades, and for good reason. The architecture is compact enough to fit the Jeep engine bay without major surgery, the aftermarket support is unmatched, and every variant in the family — from a budget 4.8L pulled from a junked Silverado to a crate LS3 making 430 horsepower — shares the same basic external dimensions and mounting footprint.

The 5.3L (LM7/L33) is by far the most common starting point. It’s cheap, plentiful, and makes enough torque to be genuinely transformative in a rig that left the factory with a 4.0L inline-six or a 2.5L four-cylinder. The 6.0L (LQ4/LQ9) is the popular step up — iron block, more displacement, more torque, and nearly as easy to source from a truck or SUV donor. Builders chasing performance increasingly reach for the LS1, LS2, or LS6 from performance car donors, or the aluminum-block LS3 and 6.2L truck variants for builds where power and weight both matter. Every one of these engines is meaningfully more capable than anything that came out of the factory, and every one of them generates significantly more heat than the stock Jeep cooling system was designed to manage.

Getting the radiator right at the start of the build is one of the most straightforward ways to protect an expensive swap. The factory YJ or TJ radiator is not up to the task — and neither are most of the generic replacements built for it.

LFT — Laminar Flow Technology.

Fluidyne’s YJ/TJ swap radiators use our proprietary LFT tube design — ½” tubes engineered to promote laminar coolant flow through the core rather than the turbulent, cavitation-prone flow of conventional tube designs. On an LS that’s already pushing the thermal capacity of a compact engine bay, the difference between laminar and turbulent flow is measurable in steady-state coolant temperatures under sustained load — on the trail, at highway speed with a load behind you, or in any condition where the engine is working hard and airflow through the grille is limited.

The core features a minimum of 16 fins per inch, and the aluminum tanks are built with walls exceeding .090″ thickness — significantly heavier than the industry standard. That wall thickness resists the flex and fatigue that cause leaks in thinner-walled units over time. Every seam is finished with premium TIG welds throughout, and the mirror-polished finish is the visible end of a build that prioritizes quality throughout. Includes a billet aluminum radiator cap, and the unit is compatible with factory transmission cooler connections.

Fitment: 1987–2006 Jeep Wrangler YJ / TJ | LS V8 swap (4.8L, 5.3L, 6.0L, LS1, LS2, LS3 and variants) | 3-row | 20″ core | Billet aluminum cap included