454 mag mpi's (Temp) 312 Fastech
 

I have one motor that runs 160-165 and another that runs 170-175. The hotter one I just put in a new 160 thermostat. I have replaced both impellers in the seawater pumps..
Should I worry. Maybe even try a 150 in the warmer motor??
They run great just picky I guess...
Thoughts????

Isn't that the tolerance of the gauge?

I'm thinking the same thing...switch the sender wires at the gauges and see what they say. Sounds like nothing to worry about thou.

My 312 oil pressure and water temperature gauges never match. I switched the sending wires to the gauges temporarily , and the high was now the low and the low was now the high. It would be nice if Livorsi would calibrate sets of gauges and senders so they would be matched sets.

temp
 

Yup!, sounds like a good idea just swaping the leads to see how it reads on the other gage...I agree a little calibration would be nice..... like they say "IF IT AINT BROKE LEAVE IT ALONE":lolhit:

Back Flush your oil coolers!
 

Give that a try, might be some junk in there, same
some water hoses. If that doesn't help then don't
worry about it! mine never matched nether.