I'd contact the Carburetor Shop in Eldon, MO. Jon is as knowledgeable as they come; he's often a contributor to thes forums. His ID is CarbKing.
I've always found the AFB numbers stamped on the vertical surface of the left front tab where the bolt hole is. It should be facing the front of the engine.
_________________________
Ed Raner
ROA #279
Heartland Regional Coordinator (Kansas City area)
1963 Riviera - Black w/ white leather
1964 Riviera mild custom
1985 Riviera - Dark Blue (stealth mode)
Some days you might have to be the statue, but other days you get to be the pigeon.