oil light on/flickering!?

slant 6 correct? drive the damn thing, keep oil in it-- your pressure is low at idle or your idle speed is too low or your oil pump pressure spring is gummed up with old oil-- no knocks or other noises run it!!
there is known issues with the slant at idle with the factory idiot lights.
what weight oil was just put in.?

there are too many variables-- have you did a correct tune-up?
you just had brake issues correct?

search this site-- great info--
if it was my car-- I would replace the valve cover gasket-- (inspect the rocker gear-- adjust the valves, then check out the carb & drive the snot out of the car) Lawrence