octaine

So... I have this 427 bbc 11.5 to 1 alum head motor........... man this is going to be harder than I thought. I guess what I'm asking is what is dynamic compresion and how would you calculate for that . In other words what is the real/best way to know your octaine needs. Oh I'm at altitude...

In the SLC area does anyone have a good av gas, or 110 hookup. On HB someone mentioned an airport up by bountiful?? I've been getting 110 at jenson oil on redwood , but it seems like the first gallon or so out of the hose is always clear like water(then turns purple). I think someone said the...