I'm shopping for all the pieces of my megasquirt changeover on my 440 and the recommended pieces for temp sensing is a chevy part that is 3/8" NPT. Is there any option for 3/8" npt on the engine anywhere? I know the port on the water pump housing is 1/8" NPT.

As a followup, is the temp port on the top tank of the radiator a reliable spot for temp sensing? I've got my temp sensor in there now and it seems like it might be reading a bit high, although I have nothing to compare it to. Today I was cruising around and it started pushing 210-220. I got under the hood and started checking around and feeling hoses to see how pliable they were. The top hose that should be going to a catch can (it's not) wasn't running any coolant out of it, and when I lifted the relief on my rad cap, there was a pressure let-off, but nothing catastrophic.

Thanks all

-Pat

Some water pump castings have an normally unused pipe plug in the top, by the heater hose tubes, that would be the best place..
Some C body models use a large switch with two spade terminals to make the cold and hot light work, and that is the place for that sender.

I think the radiator would rear a little high, but should be in the ballpark..

Don't know how I missed that one, but there are two ports right next to one another to the passenger side of the thermostat housing- one currently has a temperature-actuated switch that I'm not using, the other is just a plug. They look like 3/8, so that is where I'll go.

Thanks guys