Here is what I have learned from this experience. The original wheel is approximately 5-1/2" dia X 2-1/2" wide, counterclockwise rotation. Starting with Tim's tip above, I was able to find a wheel a bit closer in size. Murray number BW9302 is 5-1/4" dia X 2-7/16" wide, counterclockwise rotation and it was available locally. Like Tim mentioned, there is a bit of offset on the the back side of the wheel. I used a large socket (Ford 4wd lock out hub socket) and about 12 hits with a 5 pound hammer to adjust the offset. It worked perfectly. Now, I have a brand new blower wheel to go along with my band new motor.
-Tim '51 Chevy 3104 w/'56 235, 848 Head, HEI Dizzy, Corvette Cam, Split Manifold and Dual Carter YF's