LOL good point Ken.
The physical size of the V1702 - V2203 is exactly the same, the HP is the only difference. The only changes to the engine will be bolted on, its too expensive for them to make a line of engines JUST for refrigeration. Worst case you can use the throttle arm off the old engine, i'm pretty sure its the same, the only difference *may* be the govenor springs. You may want to swap BOTH the springs from the 1702 to the 1902 but if the throttle arm looks the same i'd leave it alone. If there is a problem with it, you can easily change with when in the machine, i have done it before, HEAPS of space to do it.
With the engine out make sure you give it a good clean, including the oil cooler and radiator! If the radiator was a bit iffy, now is the time to get it checked and cleaned. Its not easy to get out with the engine still in place.
Good luck!