I believe the 194 and the later-model 207's are slightly longer than the 216/235's, and there are a few other issues involved in doing that swap. Something about the bellhousing/clutch, and possibly a difference in the transmission bolt pattern? I'm sure somebody with more accurate information will chime in soon. Also, I don't think an insert-bearing conversion is made, but it might be possible to modify an insert bearing from something else with a little creative machining. Once you've got a bearing fitted to the rod, it would be necessary to regrind the crankshaft to fit the rod bearing diameter.

Don't the older engines have poured main bearings, too? Finding someone to pour, line-bore, and fit the mains to the crankshaft might be a real challenge!
Jerry

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