Hi George. Above you stated:
"I purchased the 1976 Ford Duraspark rotor for the smaller 4" distributor cap, SMP p.n. FD-115, and checked it on a NOS Duraspark distributor with the 4 inch International Harvester (IHC) distributor cap, SMP p.n. AL-482."
Searching online I can find the cap (AL482) in SMP's catalog and at Summit racing and other sites. I can't find the FD115 rotor on SMP's catalog. I find some available at Walmart.com, but not sure they really have them or not. Is the FD115 part number rotor still available or did the part # change? Just wondering where you found it and if it's still out there at most places. Good discussion in this thread and I'm looking to change to a smaller distro cap for my duraspark distro. Your recommendation on these parts based on your research was helpful! Thanks, Mike