The Stovebolt Site Forums The Shop Area Driveline am i supposed to have a transmission crossmember?

Here is that page with the 1949 frame.

I think is is showing structural parts of the frame (parts that are riveted/welded).

The transmission support is referred-to in the Shop Manual: Removal step 1-C and installation step 5-D (used through 1953).

That support is no longer referred-to in 1954, when cross-member under the engine rear (under clutch housing) was strengthened by way of of new design. 1954 Engineering Features manual.