I don't think that's correct.
Tucker used the 318 Industrial Engine,
NOT the more common automotive variant used in cars and light trucks. There are some significant differences between the two. Typically in an industrial engine they use forged cranks, forged pistons, different camshafts, different exhaust manifolds, different air cleaner, maybe a different block, different heads, different flywheel, clutch, etc. While it might be tempting to go to an auto parts store and ask for 318 parts for a car or truck of your Tucker's vintage, you may get home and find it doesn't fit.
If you look at the Chrysler 318 Industrial engine installed in a Tucker the water pump inlet is on the left (driver's) side. In the Tucker application they have the Vickers V-20P hydraulic pump, bracketry and drive belts on the right (passenger) side.
In 1970 Chrysler changed the water pump inlet to the right side, so I believe you want a 1969 and earlier style water pump. Here are some photos. The first is a photo of the lower left side of a Chrysler 318 Industrial removed from a 1980 Tucker. Note the rubber hose that goes to the radiator. (This machine came with a factory installed coolant heater. That's the part with the electrical cord attached.)
The second photo is a different view from the same side. (Note the heavy casting behind the harmonic balancer, and in front of the oil pan. That is the front single-point engine mount. Another industrial engine part not found on automotive engines.)
The third photo shows the right side. The hydraulic pump has been removed, but you can see the brackets and the belts. You can also see the fuel pump and the bottom of the alternator. Note the lack of a water pump inlet. (Sorry the photo is rotated 90º):