The octane selector is from a time when you never knew what kind of gas you were really getting. So if you got a load of bad low octane gas, you could adjust the octane selector to retard the timing to compensate for the bad gas, or advance it if you got a load of higher octane gas. The selector plate itself limited the amount of adjustment you could make so you could never get too far astray. You also used it to compensate for altitude changes, more or less air. Even though its on your 54 distributor, and is on early 6 cylinder distributors up through 62/63, it is really engineering from an earlier time and not really used much these days.
If you look at the plate you will see "A" and "R" at either end of the plate with graduations on either side of a center hash mark. If you look closely at the distributor pad on the block (you may have to wipe off a little crud), you will see a hash mark on the pad. Line up the center hash mark on the selector plate with the hash mark on the block distributor pad and tighten down the bolt. Pull the spark plugs and bring the motor up to No. 1 compression stroke (thumb over the spark plug hole works just fine). When you feel the compression starting to come up you want to either turn the flywheel by hand or use the fan belt to turn the motor creeping up until the timing mark on the flywheel and the pointer on the bell housing line up. Put your plugs back in. Trace the no. 1 wire to the distributor cap and put a vertical chalk mark on the body of the distributor directly under the No. 1 spark plug wire tower. Remove the cap. If the rotor is not pointing at your chalk mark, loosen the screw on the clamp (not the bolt on the octane selector plate) and turn the distributer until the rotor is pointing at your chalk mark. Put the cap back on. You are pretty close if not exactly on TDC. Now start the motor and check the timing with a timing light and make whatever adjustments, if any, you need.
Yes, burnish the points as noted above and double check the point clearance. I don't always remember to burnish them myself all the time but I should.
Last edited by Dragsix; 11/06/2018 6:11 PM.
