AMD x350-3570 (1970-1973) radiator support opening (20 1/2") is 5 3/4" narrower than the factory ac support of 26 1/4". On the AMD, outward from the opening, is a stamped lip where the cooling edge of the larger ac radiator would be. The location contacts of the ac radiator sitting on the support matches with the factory original. Will use a jigsaw to enlarge the opening (once my thumb has healed). Neither JEGS or AMD websites have information that an ac radiator would not fit Called AMD and talked to supervisor **** who said he would pass it up the line. At first he did not want to include the ac difference on the AMD website because he would have to do the same for other part variations. He also said he did not think it would matter that only a couple inches of cooling surface was blocked. I included this for I believe his expressed attitude is as important as the problem with the part.