There are "universal" type tranny mounts out there, but will likely require welding of some sort. Some are "bolt-in". Try Chassis Engineering or RB's Obsolete Automotive or Speedway Motors for mounts. If you can't weld or can't find someone to do it for you, you're going to have a hard time restoring an old vehicle.
If we knew where you are located, someone may be able to help you with a lead on an engine...
The Caddilac 6 is a modification you can do to the later 235/261 engines to gain more cubes. It uses pistons from a caddy V8 and rods from a 292 Chevy six. Requires offset grinding of the crank. There is an article in a previous issue of the "12 port news" that describes how to do it. Tom Langdon did the article.
A '53 engine from a truck or manual tranny car will be the last of the splash oilers.
The easiest way I know of to tell the difference is to look at the drivers side of the block. The splash oilers all have what is called an "oil distributor" which is a protrusion that has a 3 bolt plate cover. Look at your '49 for example, it should have this.
