Most guys seem to like squatty tires. I don't because they reduce ground
clearance and effective rear end ratio and I don't feel like the car handles
better. I'm using 195-75/15 tires on mine on stock wheels. They are readily
available (although size varies with brand - you need smaller ones in this size)
and look pretty normal for as big as they are, especially with the thin white
sidewall.
Did you get rubber or harder upper A-frame and panard rod bushings? I like
the hard ones (urethane, delrin, etc available from several suppliers).

Is your steering box good and tight?

Make sure your alignment is right, just a smidge of toe-in and about zero
caster and camber. A little toe-out will really make it steer all over.

I would think that the heavier sway bar would be better too.

BTW I have been driving 122s since 1970 and 220s since 1984. I have two of
them now, both 1966. To the best of my knowledge there are not a bunch of
different stock wheels for the 122 unless you have the later 4¼" bolt circle.
(Most are 4½".)
--
George Downs Bartlesville, Heart of the USA!