i believe the impeller cut "A-2" means its a AA cut impeller. the other num,bers i believe are just part numbers. a retailer/wholesaler would be able to verify this for sure.
P.S. just for comparison, my 502 in the rogers 18 is pushing the berk A/B cut at 5000rpm at 81mph. although many veriables to consider in set up. i just posted for comparison reasons.