I don't know 2 much about superchargers since I run Nitrous but I would imagine as far a detonation goes they are the same. I have my intial timing set on my 351w to 18 degrees. 21 degrees of mechanical in my MSD dizzy so total is 39 degrees. When I hit the juice my MSD box takes 4 degrees out. so I drop to 35 degrees total. I used to take 6 out but 4 seems to work. This is for a 150 HP shot. I'm sure you could get away with a little more timing but I would try it at the track. Put 1 degree into it and make a run see if you are actually improving the performance of the car at all. No need to add more timing if it really isn't helping you at all. Beware of detonation.
