I did not want to say anything about you running 15 psi, (your a big boy)
I would run the suggested supporting equipment IE, intercooler, methanol injection & a J&S Safegaurd. http://www.jandssafeguard.com/ Reason being, you are running stock cast pistons, they will explode w/medium to heavy detonation.
2800 RPM, 15 psi full boost, pretty good , glad we did not get the .96 A/R as suggested from, who was that?
It's been so long since I checked how much timing a HEI dizzy can make,, but I remember it's a lot , more than what you need for total timing.
Anyone remember how much mechanical advance an HEI dizzy has?