Here is my basic setup:
1968 Charger
440 bored 40 over with a balanced 500 inch stroker kit installed
Stock fresh 906 heads.
10.52 static compression. 190 compression across the board when adjusted for my altitude.
edelbrock performer rpm intake
Edelbrock performer cam
Holley 870 street avenger
Stock converter
3.91 sure grip
18 initial timing 34 total
5280 foot altitude here in Denver

last year you guys helped me get rid of a pinging problem because I am right on the edge of getting it to run without pinging on 91 pump gas. My problem that I still have is that I can fuel foul out my plugs real easily if I don't get it to start up right away. I also have to let it completely warm up for 5 or 10 minutes before driving it or will also start to miss a bit and foul the plugs. I'm OK with the warm up period, but not the fouling if it doesn't start right away. Once it is warmed up it runs great, the plugs look good, and the air/fuel ratio is good as well. I am not at all happy with the 870 street avenger and have battled it to get it as good as I can get it, but this fouling is so bad that once it doesn't start it won't start without cleaning or replacing the plugs.

My question is... does 91 pump gas make it hard to start a high compression motor or will it only affect performance?
Thanks for any input.