Help identify Engine

It's definitely a small block. Best I can tell is a 360 2-barrel. More engine options are on the left side of the decal photo.
Block will have casting numbers, engine size and casting date cast into the block just below the cylinder heads. The dash VIN should also be helpful, but I don't know where to find motor home applications.

Small blocks are a very tight fit in an early A-body. A big block would be much more difficult to install and work on and may involve some cutting. Don't forget to upgrade the brakes and suspension to handle the extra power if replacing the /6.