The stock 5.0/5.8 distributors need an o-ring (B9TF-12143-A / DZ-3), which is readily available.
Do they also need a gasket? I do not see reference to one in the parts catalog.
1984 Bronco 351 Holley Sniper EFI, 3 Speed Ford Auto.
1986 Bronco 302 EFI, AOD, Eddie Bauer, with 3G alternator.