When you say a small block are we talking about a 307 or a 350?
The inside width (where the bolt goes through) on a 307 engine mount (not frame mount) is 2 5/8" ,while the 350/396/454 is 2 3/8".
While the 307 engine mount will fit over the 350/396/454 frame mount the opposite will not . The 307 engine mount is shorter than the 350/396/454 mount also.
