Don't know about the '70 A-body but on the '68 - '69 B-body there are caps that open incorrectly from the originals (back to front). All of the originals have the cap open from the front of the car toward the rear of the car or windshield. The cap's retainer strap is also on the back or windshield side on the originals to open from front to back. When filling an original with windshield washer fluid, standing in front of the car, the cap is not in the way when it pivots toward the rear. Small detail but correct.