Plug a smog hole

Go to the hardware store, get 8 1/4-20 set screws 1/4 to 3/8 long, buy a 1/4-20 tap while you are there unless you already have a tap and die set. Tap the holes not quite the full length of the set screw, if you like you could use a little J-B Weld on the set screws, run them in and make them tight. Grind or flat file anything that sticks up till it's smooth. Done!