All the above engines will fit. The key thing to look at is The length of the shaft and the thickness of the shaft. If you get an engine with the same specs as indicated, it will be plug and play a 20 minute job if not then you will have to fart around and make changes.

As suggested by Rolm, get the shaft length and diameter off the original engine.

A replacement Tecumseh would be the best choice - except Tecumseh is out of business. If you do find another Tecumseh, replacement parts such as carburetors are drying up.

For this reason, a Briggs Quantum may be your best, most ecomnomical choice. These are available in all types of shaft sizes. The bolt pattern is the same as the original engine. The Briggs Quantum is fairly inexpensive and is a good running engine with reasonable power. There are tons of these in the boneyards that could be refurbished for a servicing fee.

The Honda GC is another good engine, but will not is not as common in the various mower shops. A new engine would probably need to be ordered from the distributors. This engine is more expensive than the Briggs.

The Kawasaki is a premium engine that would be expensive