318 Aftermarket Temp Sender

The problem lies within the size of the sender and probe length, totally not designed for a MoPar. That is a mechanical guage probe you have. Long and bulky.

An electric gauge will work just as well. There very good these days unlike yesteryears.

In order to install that unit, you'll need to go to the Home DePot/hardware store and get pipe fittings to fit a port on the intake and move it upwards.