Eroc, a good seven dollar Surestart will turn those numbers with the low compression head! Pick up some MORE RPM's by changing the head. I think my Norvel BM .061 turns a 5x3 up past 20k. (22?) We're talking a third more power in the Norvel. You can pick up a TD fairly cheap these days too. Heck, they're only fifty bucks brand new! More POWER!
Kinda hard to beat the value of the seven dollar Surestarts though. If they'll ship them! I ordered some more a long while back and haven't even got an email.