I was using the biscuit type than switched to the Schumacher poly mounts which are approx 20mm taller. Pass side fitted like a glove cleared everything .
Well that could make a difference. Same with the aftermarket heads, shouldn’t be a big difference but it doesn’t take much of a difference.
Yours is a ‘67? I seem to recall that the steering column jacket being longer might have been one of the “one year only” deals with that year. I know a couple guys with ‘67’s contacted me about my lower steering bearing installation with differences they had to address.