After market temperature sending unit

[Charge68]

Want to replace my original electric temperature sending unit and gauge with an aftermarket mechanical one and gauge. My motor is stock 318 2bbl. In a 1972 Charger base model. I think it is an LA motor.
Original sending unit fit a 3/8”threaded hole in the manifold beside the heater hose. New fitting are for 1/2” threaded hole.
Is there another location I can use or an alternative way to install the new sending unit?

 

[440 Charger]

3/8 npt

 

[Charge68]

3/8 npt

npt ? Nipple?

 

[beanhead]

npt ? Nipple?

"National Pipe Thread". These are the standard trade sizes that refer to pipe sizes by inside diameter, not the outside size. (Kinda like a 2 x 4 doesn't measure at 2" x 4")
If the diameter of the threaded end of the new sender is 1/2" it is referred to as "1/4 NPT"
The existing hole is likely 1/8" NPT so all you would need is a reducing adapter with 1/8" male and 1/4" female ends. Available at your local hardware/plumbing/hydraulic supply-type place.
Measure the outer diameter of the threads and go from there--
1/8" NPT = .405"
1/4" NPT = .540"
3/8" NPT = .675"

 

[khryslerkid]

Some water pump housings have an extra place for a fitting. In my case I wasn't using the heater so I used one of those ports.

One of these were required so the bulb would fit into the coolant. Some aftermarket guages will have several fittings included. This is the one I used, you'll have to do your own measuring for the one you need.
https://www.summitracing.com/parts/atm-2263

 

[Charge68]

"National Pipe Thread". These are the standard trade sizes that refer to pipe sizes by inside diameter, not the outside size. (Kinda like a 2 x 4 doesn't measure at 2" x 4")
If the diameter of the threaded end of the new sender is 1/2" it is referred to as "1/4 NPT"
The existing hole is likely 1/8" NPT so all you would need is a reducing adapter with 1/8" male and 1/4" female ends. Available at your local hardware/plumbing/hydraulic supply-type place.
Measure the outer diameter of the threads and go from there--
1/8" NPT = .405"
1/4" NPT = .540"
3/8" NPT = .675"

Thank you