[Rick Parker]

If you have the 8579 MSD Distributor with the aluminum hold downs for the cap, you can find a very good quality cap at NAPA Echlin #AL162, or an alternative brand is KEM #1553 (yellow & black box). The application is sourced for an International V8. It is a higher quality duplicate of of the early MSD cap used on the small diameter billet "Ford" distributor, these have brass contacts which hold up much better than aluminum. I use it instead of the current Red offering from MSD.
As far as the corrosion is concerned, different climatic conditions will promote it at a faster rate. High humidity will cause it to accumulate quite quickly. Do what you can to keep it dry inside the cap. If you have corrosion on the reluctor, or magnetic pickup it is best to clean it off or replace the necessary small parts.