the 70-72 Dart hoods look the same, but 70-71 have sliding plates for the 5/16" hinge bolts, and the 72 uses fixed plates, 3/8' bolts, and large holes in the hinges for adjustment. They can be swapped, but it can get frustrating to adjust the hood if you try to put a 72 hood on a 70-71, and using a 70-71 hood on a 72 will result in challenges too. Best to find a hood that is correct year version
Its interesting the subtle changes that Mopar did year to year. Like the interior door lock position on the doors etc. it makes seemingly interchangeable parts not necessarily so.
Are the bolts the same 70-72? I picked up a 72 hood and hinges for my 70 and have three bolts with larger washers than what came off my 70. I feel like I maybe lost one or mixed something up.