Classic/Antique Car Repair: ~1948 Willys/Jeep engine replacement, jeep engine, adapter plates

Question

I am trying to get my grandfather's ~1948 m38(cj3a) [i think] running again which is going to involve an engine rebuild or replacement.

It looks like it has an L4-134. I am wondering if there are more available engines that might be compatible with the existing transmission. Thanks for any advice or directions you might provide.

Much appreciated. -Shawn

Answer
As far as I know the early Jeeps like yours has the low profile body. That limits a bit what engine you can fit into the body. It was 1953 or 54 that jeep made the body taller  when they introduced the F Head 4 cylinder. Those are the only two that I know of that will bolt up to the transmission. However some of the magazines that deal with jeeps do have advertisers that sell adapter plates and kits to install different engines.
Brad