Just thought I would add my 2 cents about distributor advance calibrating..The absolute best way is to find an old-timer ( like myself ) that specializes in distributor servicing. There are probably hunderds of combinations of springs that will produce hundreds of different advance rates. Unless you have the equipment it is a long,painfull experience to get it right. Some people love to tinker and others like to get it right and move on. If I can help out please check my website
Tim O'Connor Distributor Rebuilding and Restoration - Home for more info. Have fun with those cars!!!!!!!!!!!