As the other guys have posted, there were plenty of cars running the Gas classes with stock or stockish IFS; 2 that I crewed on & 1 I helped build ('57 & '63 Vettes) come immediately to mind.
Late '50s/early '60s a lot of guys felt that the noses had to be high and the rears low to place a static weight bias on the rear because of the hard/narrow rear tires of the time. Around '65-'66 guys were moving away from that, for the handling reasons stated, as well as improvements in tires & suspensions.
On the '57 Vette, before we got to it someone had used spacers to jack up the nose; we un-did that, got the nose back down, and the car improved a bunch.