Your distributor could be installed one tooth off also. Get yourself one of those piston stops that screw into the spark plug hole from the auto parts store. You can also use a screwdriver or bolt inserted through the plug hole as long as you are absolutely sure it is installed the same each time.
Now with the plug out of the #1 cylinder (front,driver side) and the ignition key OFF (battery disconnected is a good idea for safety), turn the engine BY HAND to bring #1 up towards tdc (top dead center) on the compression stroke (both valves closed). Remove the left valve cover to watch the valves. Install the piston stop and continue turning the engine by hand until it stops. The piston has hit the stop. Mark the balancer right at the 0 degree mark on the timing tab. Remove the piston stop and continue to turn the engine in the same direction past tdc far enough that you can get the piston stop back in. Now turn the engine back the other way towards tdc until you hit the stop again. Mark the balancer at the 0 degree line again.
Measure the distance between the 2 marks and the point exactly halfway between these marks is tdc. If that falls on the original mark on the balancer your weight ring has not slipped. If it's just slightly off, just a degree or 2, that could just be production error, not uncommon. If it's off a bunch then the ring has slipped and you need to replace the balancer. An easy way to mark the true tdc on the balancer is to clean it and run a strip of masking tape from the center hub up across the top right on the mark Spray white paint on the edge of the tape. Now you have a big timming line that is easy to see plus you can look at the paint line from time to time where it goes across the elastromer from the hub to the ring and see if the ring has moved. You might need to remove the lower pulley to do the painting.
Now set your balancer with the timing marks exactly lined up and remove the distributor cap. The rotor should be pointing at #1 terminal on the cap. If it isn't remove the hold down and move it one tooth at a time, wichever way it need to go, until it lines up. You may need to use a long screwdriver to turn the oil pump shaft to allow the distributor to drop back in. Start it up and reset the timing and you are done.
While you are at it try turning the engine back and forth while watching the distributor rotor. You should only be able to turn the engine a couple degrees before the distributor starts to move. If you can turn it a lot this indicates slop in the timing chain and gears. The nylon ring on the cam gear has a habit of dissappearing on older engines. I just took apart an old engine that I could turn the crank almost 45 degrees before the cam moved. :eek There was only about 20% of the nylon left on the top gear. I don't know how the chain stayed on.
Tom
