Same issue's as you on 318 ended up at 15.7 with 4300 lb racing weight and 3.55s get the total timing up as high as it will go somewhere in the 44-45 range use Vac gauge with no vac advance ditch the carb and get a 600-650 dbl pumper Holley run N-14YC plugs the ones in the 318 are generally too cold. And you will hear get a 360 but you can make that 318 go my buddy's Dart Spt ran 14.4 with 318 and rebuilt stock heads