What aftermarket intake will work on 70-71 Air Cleaner

Don't let the spacer be a deciding factor. Half the time people put spacers on their cars and they don't do diddly s***. Half the time they actually lose performance with them. Unless your car has been on a Dyno, or has quarter mile time slips to prove the spacer has helped there's really no reason for it. A 1/4" heat insulator is all you should need.