68 cuda 340 engine color: international harvester red

I know "red" is the correct color for my engine. One page I found said this IH farm and implement paint at NAPA was the closest. They said the MP color was off, and the "chrysler red avaiilable at auto zone too.I went and found a can of the IH red and sprayed my thermostat housing , but it looks kind of weird. Anybody hear of this? I hope I don't have to get it through MP. I so hate going to that dealership.
neal