Lifeguard's engine compartment is a much cleaner, nicer version of mine. The places that he has circled in the photo is where mine are also. Trust me GM would not have spent the money for 2 senders without there being a reason. I have heard that members that put a gauge in the head the gauge reads too high compared to the water neck. I am going to put my gauge in place of the sender in the water neck and leave the one in the head hooked up. Still wonder why it was done though. Jay
Langdon explained it to me: The one in the head reads high because the heat from the header transfers to that area very easily. Mine reads high when sitting still but as soon as air flows over the area it comes down to the actual reading. I suppose if I had a mechanical fan it wouldn't be so far off but when it's idling and the electric fan isn't engaged it reads 220 or so when I know it's really 195.
I just haven't felt the need to go get a new neck to relocate my sending unit. Rather put the money elsewhere.
