Claude,
It sounds like you and I have very similar engines. I started out my build running 100ll also. I started with 20cc domes and it was too much compression for the octane rating of 100ll. I was backing plugs out...
Just saying to be careful here. I think I was at 180 psi with 100ll at the time. I ended up going to 22cc domes for reliability and longevity. I didnt miss the extra down low grunt from the switch all that much.