Are you referring to a 1950 Chevrolet 3600 truck?

If it is a low pressure 235 it would be almost a direct bolt up (maybe have to deal with the front motor mount).

If it is a 54/55 truck engine, it's a direct bolt-up (using your clutch housing and clutch assembly).

If it is a late 1955 or newer 235, you'll have a few modifications that you will have to do. This topic arises about twice a week. You might want to look at previous posts in the engine/driveline forum.

If need a running truck in short order, your quickest solution is the rebuilt 235.

What year 235 engine do you have?