There's plenty of other places to save additional weight if you haven't already been into it - look at behind the kick panels, tops of the rockers under the sill plate, inner quarter panels, drilling holes in the rad support, on and on. I've got a road runner here built out of Arlen V's shop and they treated sheet metal contours like cut here lines. They even trimmed extra metal off the back of the dash frame and cut out all but the cover of the ash tray and riveted it in place. Cowl is smoothed (no vent) and the underside of the cowl is gone. Keep after it an ounce at a time and it'll add up for you eventually.