When I purchased my Pantera in 1977, the previous owner had converted the radiator to a single pass set up. With the worn stock engine and low compression that the 1973 models came with, this radiator design actually worked. When the engine was rebuilt and the horsepower was increased, the single pass radiator became useless. It couldn't cool the engine at all at temperatures above 80 degrees ambient. When I switched the radiator back to a stock dual pass system the cooling improved greatly. It wasn't perfect, but I was at least able to live with the set up. The basics of cooling a Pantera come down to where the cooling problem is. If it is running hot only at low speed, then it is an air flow problem. If it is running hot only at highway speeds, then it is a cooling flow problem. If the engine seems to be running hot all the time, then you might have a leaking head gasket of several other issues.