Link to Beck's ad in the Inliners' site. Other intersting reading includes Roger Huntington's book from the early fifties and several articles that were in Hot Rod Magazine from the early fifties. Reprints of Roger Huntington's book are available, and I have some of the old HRM aticles. Back then, it was standard practice to bore the 216 0.060" over, as Christopher says, which give about 224 cubic inches.
If you could find one of the early 235s in some of the '41-49 trucks you can get 248 cubic inches with the the tall side covers.
Hoyt