Drilling and hammering on vintage knuckleheads can be a traumatizing experience. Don't fuck it up. Dad made a special pin(rivet) to lock the intake flange. We peened it from the inside, smoothed it out and formed it to a stock-like appearance. Now the flange is tight and secure. PJ-1 Satin Black and it's ready for the valves. Late Model Knucklehead: The last one, and the best one.