Are swivel foot valve adjusters on a bone stock 1600 worth installing or is it just overkill?
I am thinking of the elephant type.

overkill.

Yer, I was thinking overkill. I have to take the heads off to fix some push rod tubes. just thinking out loud.

yep overkill.. woftam

for an old engine/valve train, maybe, but definately helps valve stem wear if fitted when heads are fresh IMO.