The curve is probably wrong for the current initial setting. Easy shade tree check method/fix. You can mark your total timing point on your balancer with a sharpie and you do not need to purchase anything.
Use a cloth sewing measuring tape, a piece of string, whatever. Just wrap it all the way around the balancer with "something" then lay it flat to measure the balancer circumference with a common measuring tape. You multiply this mesurement by .1 to get the distance from the timing mark (slot) to the target of 36 degrees on the balancer. That sharpie mark you add will be on the balancer to the RIGHT of the TDC slot on the balancer.
Disconnect the vacuum advance (plug the vacuum leak). Hook up the common timing light and shoot the balancer while you rev the engine up until the ignition stops advancing, maybe 3500 or 4000 rpm or where ever it stops advancing. With the light flashing and distributor at full mechanical advance you rotate the distributor to line up the sharpie mark with the "zero" on the timing tab pointer then lock down the distributor. Hook the vacuum advance back up to a manifold vacuum signal.
You will probably need to play with the RPM screw on the carb at this point to get it to idle right because your inital advance will likely be much less than it was when you started. Where ever the advance is now is where it should stay untill you can recurve the distributor properly. The distributor will need to modified to remove the available centrifugal advance (reduce slot travel) in order to PROPERLY run additional initial advance that the engine will "like".
A properly recurved distributor will allow you to run more initial, start the centrifugal advance no sooner than 1200 RPM and finish advancing at about 3000 RPM.
-Mark.
