This is a very interesting discussion. We run at Rye House and currently on a 20/81 gearing (sister to 19/77 which is common). We have the Alfano tapped in to the ignition switch after wrapping around the HT lead proved to be very hit and miss. I can see my son is entering Stadium at 6500 and had been toying with the idea of dropping down to 80 or 79 but worried about bogging him down out the corners. We have been having an issue with oil coming out through the fuel pump and I noticed when he wasn't entering at 6500 we didn't see the issue anywhere near as bad (still get a bit in the feed pipe)
Think we definitely need to drop down a tooth or two and get it tested.