Rotor/Reluctor Phasing Question

Reddartowner,In your post #17 you may find that your Vac can on you distributor is adjustable to set total vac advance. You insert a small allen wrench(I'm sorry I don't remember the correct size)thru the port opening to adjust.It has been a long time but did this on a 74 318 to cure pinging.

The vac can on the distributor is adjustable. We have already put 3 turns CCW into it, but with 20 inches of vacuum at idle, it still adds about 28 degrees. How many turns CCW can we go before the adjustment runs out ?