Gibson is correct. There are factory washers under the wing nuts on a '69 Ramcharger air cleaner lid. Mine is a 4 barrel (383 Super Bee) car with the oval air cleaner just like the six pack ones except the base is for a 4 barrel instead of 3 two barrels. So, I imagine the six pack cars are probably the same? I've owned my Bee for more than 47 years.