A couple of good points are made in this thread.
Run W/M injection as Bill Dedman does to ward off detonation. And like Bill, run some gears in the rear, 3.55 or numerically higher. Less strain and load on engine, equals less chance for detonation.
X2 on using aluminum heads as Cudavert suggested. A tight quench will help ward off detonation.
Run a 6BTM (or equivalent) ignition box, use non projected tip spark plugs, and try to keep the engine as cool as possible.
Swinger340, what cam are you running?