I have a 1990 Mk VII Linc with a positive displacement supercharger. I have used 104+ in it when I run the 8 lb pulley, which helped, but still wasn't perfect. I ran it with a full bottle in 20 gallon tank for that way for about 3000 miles. Plugs turned orange, other than that, no problems. You might try it and see how it works. I also used a tank of race gas once to see if that would help. I don't think my injectors put enough fuel down. You can also try retarding the timing a bit to get the burn to go sooner to avoid knock, however, that will raise engine temp, and about 3 degrees is worth 30 hp. I also had a crane spark brain that would backup the spark electronically and that helped as well, but you lost a lot of go when you had the ping completely eliminated. Now I just run about a 4 lb pully and get no knock and for the most part have no problems. Another old hot rodder trick is to run a 160 degree thermostat to make the engine a bit cooler to avoid pre-ignition.
