You may need to get a pipe union and a short nipple and screw them into the intake the screw the temp bushing into the union. I can't imagine that the coolant passage is small enough that the temp probe bottoms out in there though. Or you could plug that hole and get a Pipe "T" and screw it into the heater hose "hole" in the coolant passage with a short nipple and run the temp sensor into one side of the T and the heater hose nipple into the other side. I've done this several times over the years. I use a brass T though and polish them.
