I went to the parts store a few years back to buy a coil for my pick-up, I approached the counter and asked for a 12v internally resisted coil. The lady asks me what it it for and I say it doesn't matter, she says it does because different companies use different coils, I says it doesn't matter an internally resisted 12V coil is the same regardless of application. She informs me that she cannot look it up without knowing what it goes on, because she wants to ensure that the part she pulls is the right one. So I tell her it is for a 61 IH. She looks at her computer screen and tells me she can't help me because the computer only goes back to 68, so I say can you look up a 68 IH then, and she then starts typing and ask me who made it and I say International, and she says yes I know that I mean who made it, Ford, Chevrolet, who? I say you know what don't worry about it, she asks if she can help with anything else and I say sure I need to get a coil for a 68 Camaro, she looks it up gets me a coil and I say thank you very much. I go home and put the coil on my pick-up and guess what, my IH runs just fine with the Chevrolet coil on it that I was assured would bring ruin upon me if I used it.