You might consider what I did. Purchase the Pertronix D135700 y block distributor. All the connivence of the MSD and half the cost and it’s new not a rebuilt cardone Bought mine from Summit and couldn’t be happier. 

Duane

A Pertronix conversion is one of the easiest and most cost effective upgrades you can do to a Y-Block. My 55 Tbird had it's original Load--A-Matic distributor when I bought it. It ran like crap.   I found a 1957 Ford 272 distributor in good condition and swapped out the points and condenser for the Pertrontix unit.  If you buy the right Pertronix coil, you can ditch the resistor too.  Coupled with a modern carburetor, the distributor and carb swap transformed my motor. I never adjust the points and it runs great.  Just so you know, most of the auto store points and confessors you buy today are Chinese Junk. If there are any Chinese on this forum, I apologize. Perhaps they are making them on Mars for all I know?  Where ever they come from,  they are pure garbage.

thanks, have the parts to put the points cam back in the distributor,as you indicate the ring sits over the point cam

Dura Spark in a Y-block?  If so, then your distributdor should be the latest y-block distributor with the triangular cast neck that was converted from points/condenser to duraspark some time in the past.   You would thereforee haveto go back to points cam and pivot plate in order to accept the magnet wheel and pickup assemble of a Pertronix. Unless Pertronix now makes a conversion for a Duraspark distributor.  Or, find a good Y-block distributor.  If it's just the Duraspark box that's an issue, simply replace that with an MSD 6A box. The Duraspark will pulse an MSD box nicely by just a simple wireing change.  The MSD box comes with full instructions on how to do this exact thing.  This may save some time and possibly money.   

64F100 57FAIRLANE500

Easy peasy, just follow the instructions. You may find it easier to do with the dizzy on the bench.

getting rid of the ford dura spark, hard to get parts and, even tho I was a fan since changed my support. is ther any issues installing pertronix in my ford dist. thanks for any tips