It has taken a while but I did install the ford 3/8" npt sending unit. It work at first then as the temperature rose and the thermo opened the guage was a 1/3 of the way up, when the themostat open, the guage would peg to hot (water was 175 at the sending by ir meter). Measured the ohms and tried some resisters, after many tries I settled with 47 ohm 5 watt resister. After 5o min drive home from a show, I shot the manifold with the ir gun and it said 179 - guage read on the e of temp. Decided to settle here.
When testing, I was Idling the engine and a lower ohm look ok. But I forgot about the voltage change on reving with a generator. Measure 12.6 v at idle and 14.8 on reving.
Well tooks me a month to finally get here and it works ok. Have some one coming to look at buying the 56 3200 next week because I got a 1950 chevy show truck and really need the storage ( don't want to part with it but I store everything indoor in the winter here). I hope this helps someone, as this site has been very helpful to me and I have recomended it many times at shows. Thanks to everyone again.
