What would be my favorite engines to swap into a Jeep CJ-3B?

One of the American-designed vehicles I like the most, with features that contrast with most of those landyacht imagery from the full-size cars of its day, the Jeep CJ-3B has a convenient size which could still render it a good base for a daily-driver project. On the other hand, a stock 2.2L Hurricane F-head gasoline-powered engine was already quite outdated even by then when OHV designs prevailed. The first upgrade I would consider in order to make a CJ-3B a reliable and preferably more fuel-efficient all-around commuter is an engine swap, to which 5 engines could be favored by me.

1 - Perkins 404: available either in naturally-aspirated or turbocharged versions, this Diesel engine could be regarded as a natural evolution considering the usage of the Perkins 4-108 engine in some Spanish versions of the CJ-3B. All the 4-cylinder versions of the 400-series Perkins engines come in the a 2.2L displacement, just like the gasser it would be replacing, and it's also worth to notice the gear-driven OHV valvetrain and injector timing are not so failure-prone, so the maintenance would not be too significantly more complex;

2 - Yanmar 4TNV88: a comparable engine to the Perkins 404, it has been widely fitted not only to stationary/industrial applications and agricultural machinery to be also found on sailboats, to which once again the Perkins 4-108 had been widely used as auxiliary power. Available either with natural aspiration or turbocharging too, this engine has also been used for swaps into compact trucks even in the United States, even though some performance upgrades are frequently added in order to meet the requirements for these rigs which even in stock form are larger and heavier than a CJ-3B;

3 - Chevrolet 153: even though it's also an old gasser just like the Hurricane, the gear-driven OHV valvetrain is an improvement over the precarious intake-over-exhaust approach. This has actually been one of my favorite engines for a long time;

4 - Volkswagen air-cooled flat-4: even though it may seem quite weird, a "Veep" still attracts me. Even though the most usual approach for such swap was to replace the entire frame for a shortened Volkswagen one with a makeshift rear engine compartment, trying to fit the engine upfront would not be discarded immediately;

5 - Hatz 2L41C/2M41: even though a 2-cylinder Diesel engine may not seem so attractive at a first glance, its 1.8L displacement range is once again comparable to the Perkins 4-108, while the air cooling is also quite tempting. A major downside is the weight of those engines, even though the small amount of cylinders may fool someone to believe it would be a hassle-free engine swap...