Evidense of Z-28 stripes in trunk lip and hood lip or in cowl? Under all the repaint? 4 piston calipers on front? 12 bolt rear? 3/8 fuel line from the tank? What shifter? Original colors, int and ext.? Other options? Let's have it with a full description! The casting no. will only tell you it "could" be a 302, could also be a 327. Look to the stamped no. in the front. Better yet, get the book Chevrolet by the Numbers and start from scratch, carb, water pump, intake, distributor, etc.