well what can I say..was under the impression 50/40 was the helix that was good.Others say to low a finish go to a finish of 45,now it is a finish below 40.Looks like I'll be selling the 8bu's and go back with stock setup..at least it is consistent and rpm's are dead on and can hit more mph then with my 8bu's.I ran with a 49/45 today,dropped weight in the primary and rpm's are basically close.But with the extra 5 inches of snow here,there will be no speed runs going on now.Going back to the stock setup for weekend..betcha I pull more mph then the 8bu's this weekend.