Boiling Point
Building a period-correct cooling system for your GM
Wayne Scraba - November 22, 2012 10:00 AM


Today, vintage Harrison radiators are next to impossible to find. But you can buy a perfect made-in-the-U.S.A. reproduction from the folks at Classic Industries.

Following manufacture (soldering) the radiator will see rapid surface rusting. It’s not a big issue though – Classic Industries simply recommends you glass bead the tanks and then paint the assembly with radiator paint.

The tanks and mounting brackets are exact copies of the original. This is a four-core heavy-duty radiator for a Camaro or Nova.

You can see the Harrison logo is accurately reproduced on the side tank.

The gooseneck inlet at the top of the radiator (and yes, very late big block Novas circa 1969 could in fact have a gooseneck radiator, just like a COPO Camaro).

A commonly overlooked piece is the drain petcock. This one (again from Classic Industries) replicates the original.

Vintage radiators such as this were not set up with coolant recovery systems. The radiator had an overflow system and used a ribbed hose to direct the overflow.

The lower hose required for our application came from Pace Car Jeff. Jeff’s hoses are exact replacements and they include reinforcements as per originals.

Here’s a look at the matching upper hose. You can see how the correct part numbers are stamped on the hose. Note that the stamping isn’t perfect. That’s how GM did it way back when.

Check out these Witteck hose clamps from Pace Car Jeff.

They’re date stamped (2/69). You simply have to request an appropriate date code and Jeff will stamp it for you.

The 3969811 casting number on this water pump is appropriate for a wide range of 1969 and later “long pump” big blocks (Chevelles, Camaros, Novas and Impalas).

The date code for this big block water pump is “D-29-9”. Broken down, it’s April 29th, 1969. The month codes are as follows: A-January; B-February; C-March; D-April; E-May; F-June; G-July; H-August; I-September; J-October; K-November; L-December.

Up front, the pump is fitted with appropriate pulley and fan studs. Both the pump and the studs are available from the folks at Classic Industries.
We’re slowly (and we really mean “slowly”) building a modified Nova.
We started with a small-block little old lady car and the goal is to eventually build something like we could have built way back when. The Nova will eventually be a big-block- powered machine that will have the flavor of the early ’70s.
When it comes to the cooling system, we really need to keep the beast cool, but we don’t want to stray too far away from the production look. Now, since the car in question is a very late build (it could very well be one of the last cars built for the 1969 model year), it also means something like a big four-core radiator was a possibility. But where do you find one that looks right?
The same applies to all sorts of detail parts including the radiator support, water pump and even items like the hoses, hose clamps and other little hardware. Truth is, there are actually a number of really good vendors out there who go out of their way to provide decidedly accurate top quality reproduction pieces.
Case-in-point is the cross section of cooling system parts we rounded up for this article. Some of the parts are for a rather rare combination while some are commonplace. You might be surprised at what’s out there. You can even locate hardware that is appropriately date coded. And maybe best of all, you don’t have to reach your personal boiling point when searching for hardware.
