In the past it didn't matter if they were adjustable or even worked just that they looked good. We would disconnect or cut the diaphragm arm inside,plug the nipple before putting the hose back on .That was because many of us would gut the insides of the distributor and put in a centrifugal advance and duel points for better seat of the pants acceleration . We also plugged the the thermactor ports and gutted the smog pump to make it free wheeling. Everything looked like it was assemblyline but with added performance.