The L29 454 heads have a lot of sharp ridges that would lead to detonation, especially with any carbon buildup. Go back to the first couple pages of this thread and see how I laid back the chambers and polished everything. It will be very resistant to preignition. So even with 87 octane, it should be happy with 34 deg at wot, and 30-40 at part throttle cruise. I'm not sure why BB would be unwilling to adjust it for me.