| Radiator Specifications |
| The 1966 specifications are for commonly available OEM reproduction radiators. Though 4-core radiators are listed, many stock Pontiac applications used 3-core radiators. OEM-style 1964-1967 radiators used a downflow design that featured tanks located on the top and bottom of the radiator. The PRC radiator features a cross-flow design and has upper and lower fin covers. |
| Radiator Specs | '66 Standard | '66 HD and A/C | PRC Custom |
| Construction | Brass/Copper | Brass/Copper | Aluminum |
| Type Flow | Downflow | Downflow | Crossflow |
| Core Rows/Width | (4), 1/4-inch | (4), 1/4-inch | (2), 1-inch |
| Core Depth | 2 1/4-inches | 2 1/4-inches | 3-inch |
| Core Width | 15 1/4-inches | 17 1/4-inches | 20 1/4-inches |
| Core Height | 23 1/4-inches | 23 1/4-inches | 20 1/4-inches |
| Overall Width | 25 1/4-inches | 25 1/4-inches | 25 1/4-inches |
| Overall Height | 20 1/4-inches | 20 1/4-inches | 20 1/4-inches |
| Weight | 23-pounds | 26-pounds | 16-pounds |
| Shawn Kenney, of PRC states, "Using distilled water in radiators is very important to ensure that the minerals in tap or bottled water don't react and facilitate corrosion via electrolysis. In addition, the popular acid-based cooling system additives are destructive to aluminum. In essence, the acid smoothes out water jacket imperfections so that bubbles don't form as readily, but in the process it attacks the aluminum." |

One of the aluminum spacers in the Alternator Relocation Kit is slipped over the stud and then the alternator slotted arm is mounted to the water pump. The other spacer, washer and 1/4-inch headed bolt are placed through the slotted arm and threaded into the alternator.
Recommended Tools
Standard socket set
Standard wrenches
Allen wrenches
Cut-off wheel or grinding wheel
Electrical Tester
Electrical service tools (wire cutters, crimp tool, soldering iron, solder)
Recommended Parts And Supplies
Thread sealer
Fel-Pro timing cover gasket set, part number TCS-13383 (optional)
1/4-inch convoluted tubing
Electrical tape
RTV gasket maker
Conclusion
While technology has advanced significantly over the past four decades since the '66-'67 Pontiac A-bodies prowled the streets, one thing is very consistent: A cooling system that operates at peak efficiency often makes the difference between an enjoyable cruise on the town and/or success at the dragstrip, versus a frustrating day dealing with a hot-running car or, even worse, being stranded on the side of the road. HPP believes in real-world testing and the best way to do it with a cooling system is to perform it in the heat of the summer. In Part II, we will test the effectiveness of the new cooling system in August heat in Texas and explore common cooling system foibles and solutions.
 The belt is then slipped over the alternator and pulley, and the two 1/4-inch headed alternator bracket bolts are tightened. After verifying that the belt lines up properly with the pulley, a pry bar is employed to stretch the belt to the proper tension while the bolt on the slotted arm is tightened. |  PRC specializes in custom-built high-performance aluminum radiators for street rods and musclecars. They built this 2-row, 1-inch tube radiator for $385. The tanks are located on the sides, indicating that this is a cross-flow design. An aluminum fin cover was welded between the tanks on the top and bottom to cover the exposed core, allowing a traditional '64-'67 radiator mounting. |  The radiator is constructed of high-quality aluminum with thick-wall tanks. Note the expert aluminum welds and the cover fitment over the top of the core. |
 SPAL supplied its 16-inch electric fan (PN 30102047, retail $157.95), 185-Degree Thermo switch, and Wiring Harness (PN 185FH, retail $55.95) to replace the factory unit. Also included is a heavy-duty SPAL relay that, when used in conjunction with either a 185- or 195-degree thermo switch, will automatically switch on the fan to ensure proper cooling. |  PRC built a shroud (retail $100) specifically for the SPAL 16-inch fan to maximize its efficiency. For installation, the shroud is removed from the radiator and the fan is placed into the pre-cut hole. Four 1/4-inch holes are drilled, then the fan is mounted with 1/4-inch long bolts and nuts with nylon lock washers. |  Trial-fitting the radiator reveals that only a few minor alterations are required to mount it. One-inch spacer nuts are placed under the factory lower radiator mounting brackets to raise the unit up to the factory height. The radiator is then dropped into the rubber isolator pads, and the top hold-down bracket is trial-fit. |