X2 with getting YOUR SPECS to a converter builder. Don't bs them on the specs either, or no matter whose converter you get, it'll likely be wrong. Seen it too many times where the wrong information was supplied and then had to put up with po'd customer. Your cam maker also has probably made a suggestion as to the stall that will best with YOUR SETUP. Trying to guess what stall is needed for you is a crapshoot at best.