I should elaborate more on what I said earlier about the Duraspark distributor. A Duraspark distributor is a Motorcraft. Most small block and big block are Motorcraft. Some Y-Block distrributors are Motorcraft. Where Motorcraft distributors are concerned, I believe it is only the shaft and gear that is different.
Swapping from Autolite to Motorcraft, or maybe even some Autolite to Autolite will involve a lot more because many of the parts are different and when it gets down to it, may not even be worth the attempt when MSD and Mallory make distributors.
Lawrenceville, GA