rich
it will kill them cats

hurc ast

You indicate that you have no aftercooler so I'll assume your working with a
turbo rather than something positive displacement.

I also see that you seem to have a good grasp on the effects of "walking too
close to the line" as far as mixture is concerned.

Unless you're already there, go with the coldest plugs you can find.... if
you are running a decent multistrike, high output ignition, don't get too
shy with the gap. If you back the advance out a little (total or initial,
you'll know best if you are sure of your curve), it will probably give you
some margin for error. If you can, do a really hard pull with fresh plugs
and do a "hot drop". Cut the ignition at the end of the pass, push in the
clutch or put the trans in neutral and, at the same time, keep the throttle
wide open to reduce the vacuum signal through the carb(s). Pull the plugs
and inspect them with a good magnifier. You may have to repeat this process
a few times, but it should ensure that you have little in the way of bad
kharma. After you establish your mixture, start bumping you timing to find
the ideal initial and all in numbers. I like using a G-Force accelerometer
for this and you can work through different rpm ranges to fine tune the
curve.

Hope this is what you were after....

Unfortunately, you'll need to walk a tight rope.  At your boost and
power levels, with no after/inter cooling, I wouldn't go any higher than
12:1.  Keep in mind that summer temperatures make things worse for
detonation.  If you want to add a nice safety factor and spend little
money then look into water and/or alcohol injection.  I use it on my KB
blown Mustang and have run up to 16 psi without any detonation problems.
 It is very effective when used properly.