Hey Weeds - If your heater core is the round type, forget about trying to get it fixed. I talked with Harrison Radiator Co. about those. They stopped making them in 1962. They were used in postal trucks after Chevy stopped using them. The radiator shop guys can't fix them because they can't get inside of the circle unless the leak is on an outside edge. Those "universal" heaters that you see are real close to the heaters that GM actually put in the AD trucks. Usually a dealer "add on" . They measure 6 3/4" wide x 6 3/4" tall x 7" deep. You can get it from "Southern Rods", cost is a little over a hundred bucks including the 2 speed switch. I got them in my '49 1/2 ton Chevy pickup and in my '51 BelAire.
