I went to install a radiator in mint condition that I happened to snag out of a junk car for like $20. However, I noticed the drain plug was somewhat screwed up, so after much labor, I finally removed it only to find that the drain plug was not the same as the one on my old radiator. The old radiator plug was red, and this one was white, with what looked to be the same style as the red one, just different thread sizes. The radiator is a Behr, and I have looked on the buy parts link for another one, but to no avail - across all the models. The radiator was removed from a 300e like mine. Please help - why is there a white drain plug, and will the blue one be a perfect substitute, it looks like it has the same threads as the white one.

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87 300E
202k on the clock