[Dave at Pelican Parts]

Do those fit in stock early or late style rocker arms? Are modifications required? The 73+ ones are larger in diameter, and won't fit in the 70-72 rocker arms.

Do these have "swivel feet", or are they just round-ended screws like the stock ones?

Evidently 911 swivel-foot adjusters fit into early rocker arms. But you have to trim the area where the adjuster goes, or shim the rocker stands to restore the geometry.

--DD