Difference between early (52 or so) and late (56-57) King Seely temperature senders.

GrimGreaser

Out of curiosity...  I have 2 temperature senders, one from my old '52 engine marked 'KS 2' and another from my '56 engine marked 'KS 7'. For my custom gauges I calibrated the KS-2 a while ago and installed it in the engine. However, when the gauges were all installed it read really high (240° when everything else said 160-180° at most). Before installing the gauges completely, I calibrated the KS-7 with the actual gauge setup separately off the car and got a completely different curve.  Long story short (too late) I finally used the KS-7 curve for the KS-2 and am within the real of reality now as far temperature readings go.  Are the 2 senders measurably different?  They have different markings and I assumed so. I haven't found any further info on them though...