I'm preparing to install an Old Air air conditioning unit. The current radiator, an original Harrison mid-'60s big block 4-core brass and copper radiator, just wasn't up to the job. Nor was the puny fan and abbreviated shroud. 

When cooling a high performance engine, which produces a great deal of additional heat when compared to a stock engine, what most people don't consider is the critical cooling ability at idle. Even with adequate capacity in the radiator, a custom shroud and aggressive 7-blade fan, about all the air that will move at idle is 1000cfm, barely enough to cool the engine at idle without A/C here in the desert.

That's why I purchased a 2-core, double-pass aluminum radiator with transmission cooler (the current trans cooler is mounted in front of the existing radiator) that duplicates the existing radiator dimensions to eliminate fabricating new mounts. I'll cool that with a 16" electric fan that produces 2700cfm, mounted to the driver's side of the radiator to clear the water pump, that's controlled by a 195-degree thermostat. Photos as install progresses.

        Old Radiator     New Radiator         

The new radiator has the fill spout on the opposite side of my existing overflow tank, so I ran the overflow tube in front of the radiator where it won't be seen and fastened it at the top, leaving room for the yet to be received A/C condenser.

Other than where it comes off of the fill spout and where it goes into the overflow tank, the overflow tube is well-hidden.  

Still have the fan to install, that's on backorder from Howe Racing, but the new radiator has a much cleaner appearance in the engine compartment. I'll package the wiring above the top of the radiator into a carrier.

Much cleaner look

Alternator upgrade is next

Fan installed, but it's temporary. This one moves about 1600cfm. Fine for this time of year, but the permanent fan moves 2400cfm and is on backorder. If that won't do the job in 115-degree summers at idle with A/C on, I'll go to a Lincoln Mark VIII that moves 5400cfm. Either way, I'm going to have to upgrade the alternator to at least 120amps at idle.

Spal fan installed, 185 degree fan thermostat installed on passenger side of radiator where transmission heat exchanger is located. I also installed a toggle switch under the dash to allow me to manually turn the fan on. 

I currently have about 20 hours of labor in removal of old parts and the install. Big time consumers are:

    Measuring/cutting side mounts to fit 

    Drilling mounting holes in the radiator mounts and radiator support

    Drilling holes in the radiator support to pass through the overflow tube

    Methodical cutting of upper and lower radiator hoses to fit. Holding the lower in boiling water 

    for initial fit

    Sanding/painting water pump pulley, horn and thermostat housing

    Wiring the fan

I've used all new grade 5 and 8 bolts and nuts with SS flat and lock washers throughout the install.

When the electric fan arrives, I figure fours hours of installation time. That'll include a new fuse block directly off the battery for the fan and A/C and wiring two key-on relays for them.

Once everything, radiator/fan/AC, is completed, I'll convert the existing black hoses to SS braided line with AN fittings. 

Results were: Griffen - $718

                    Ron Davis - $518

                    McCullough Engineering (Howe Racing Radiators) - $475

2700cfm 16" fan - $140 (three-year guarantee, important after using some of the el cheapo Summit fans in the past on other vehicles)

Fan wiring harness and thermostat - $40

McCullough Engineering (no affiliation) http://www.alumrad.com