Are you doing an engine swap? There may be a cooling solution that’s easier to order than you
think.

Flex-a-lite is making your next engine swap just a bit easier.

While it’s common to find parts such as motor mounts and headers to accommodate engine swaps, it’s usually a challenge to find a radiator custom built to meet your needs. That’s no longer the case with a variety of engine-swap radiators and electric-fan combos available from Flex-a-lite.

Flex-a-lite builds its radiators in-house, giving the company the ability to do custom configurations to accommodate engine swap needs.

Because Flex-a-lite builds its radiators in its Fife, Washington, headquarters, the company can make a number of changes to its Flex-a-fit radiator configuration to accommodate an engine swap in just two weeks. This includes custom variations to a direct-fit, bolt-in radiator for a specific application, as well as universal radiators that a customer can fit to whatever chassis he or she is working on.

One common request for engine swaps is to relocate the radiator inlet and outlet, and often to resize them. Among these, the GM LS engine is one of the more preferred engines, and often the water pump dictates that the inlet and outlet be on the same side of the radiator. For this, Flex-a-lite builds a dual-pass radiator–installing a block-off in the side tank with the inlet and outlet–forcing the coolant to cross the radiator twice before it can return to the engine. This provides increased cooling in addition to placing the inlet and outlet in position to make hose connections easier and cleaner.

Flex-a-lite makes a direct-fit radiator for ’64-’67 Mustangs (left). People who swap to
the popular 302 engine, though, need the radiator outlet on the driver’s side. Flex-a-lite has accommodated this configuration through its custom radiator program, and has had so many requests for it that it has now been added as a direct-fit part number.

Here are some of the options available when ordering a custom Flex-a-lite radiator:

• Choose alternate inlet and outlet sizes, such as 1-1/2 or 1-3/4 inches

• Modify the position of the inlet and outlet on the tanks

The LS engines are very popular, and not just for swapping into Chevy cars. It’s very common for these engines to need both the radiator inlets and outlets on the passenger’s side. Flex-a-lite accommodates this by building a dual-pass radiator.

• Have both the inlet and outlet on the same side of the radiator

• Choose from a straight or an angled inlet and outlet

• Specify a single-, dual- or triple-pass radiator

• Add additional ports, such as 1/4-inch NPT bung installed in one, both or neither side tank (these are handy for drain petcocks and also to install zinc anodes to help protect the aluminum radiator from internal corrosion caused by electrolysis)

• Add an additional tube in the side tank for a steam-tube or expansion-tank connection

• Angled side tanks for hood clearance or other obstructions

• Shave sections of the exterior T-channels

• Modify the position of the filler neck for hood clearance

If you need multiple radiators with the same modification, you can work with Flex-a-lite to develop a specific part number. For example, one of the first engine swap applications the company addressed was for later-model Ford small-block engines being fitted into early Mustangs. Working with one vendor that builds a lot of early Mustangs, Flex-a-lite created a variation of its direct-fit Flex-a-fit radiator and electric-fan combination to place the radiator inlet where it would need to be for a simple and clean installation.

Moving the inlet and outlet to match the port direction on the water pump can greatly simplify radiator hose selection and create a clean installation. This also makes it easier to find pre-formed hoses that will fit well.

If your engine swap calls for a universal radiator, Flex-a-lite provides 90-degree mounting brackets that easily slide up and down the radiator side tanks. This gives you great flexibility in mounting options.

Here’s the complete list of radiators that Flex-a-lite now offers for early Mustangs:

Part Numbers

50064  Radiator only–’64-’66 Mustang, passenger’s-side inlet and outlet

50164  Radiator with electric fan–’64-’66 Mustang, passenger’s-side inlet and outlet

50064R1 Radiator only–’64-’66 Mustang, driver’s-side outlet and passenger’s-side inlet

50164R1 Radiator with electric fan–’64-’66 Mustang, driver’s-side outlet and passenger’s-side inlet

50067  Radiator only–’67-’69 Mustang, passenger’s-side inlet and outlet

50167  Radiator with electric fan–’67-’69 Mustang, passenger’s-side inlet and outlet

50067R Radiator only–’67-’69 Mustang, driver’s-side outlet and passenger’s-side inlet

50167R Radiator with electric fan–’67-’69 Mustang, driver’s-side outlet and passenger’s-side inlet

There is a host of options available from Flex-a-lite to make the radiator fit your engine swap needs, including angling the bottom of the side tanks to fit snugly in the chassis.

The Flex-a-fit radiator from Flex-a-lite includes a patented side tank design that helps pull heat out of the radiator more efficiently. The side tanks are made from extruded aluminum and feature fins on the inside and outside. These side tanks transfer 135-percent more efficiently than a typical aftermarket aluminum radiator tank and 41-percent more efficiently than a brass
radiator tank.

Do you have a custom application for which you regularly need a custom radiator? It may be worth your time to contact Flex-a-lite to see if your custom need can be converted into a regular part number to save you time–and potentially money–over the long run!

An upsell to consider when installing aluminum radiators is an additive to help protect the aluminum against corrosion. Flex-a-Chill from Flex-a-lite was designed specifically to protect
aluminum in the radiator as well the engine (anywhere aluminum comes in contact with coolant).
It’s also racetrack approved!

by Cole Quinnell