"It was the exact same frame, "
Nope. Mavericks are "Ohio" frames, if I remember the codes correctly. They're the last vestige of the Falcon.
Pintos, I don't remember the frame code but they're a beast in and of themselves. Those who love to call the Mustang II a pinto must also remember that the only shared component between the two is a small section of rear floorpan.
It's easy to see; Mavericks have shocks and springs attached to the upper a-arm with a terminus in the top of the shock tower. Pintos have it attached to the lower arm with a terminus on a horn attached to the K-frame.
Pintos never came stock with a V8. They did, however, eventually come fitted with the 2.8 V6.
Mustang IIs almost didn't come with the V8 either; that's why a lot of parts are split 1974 and 1975-later, there was a minor redesign to get the V8 to fit. Same with the Maverick and the 1971 versus 1972 onward models... those are easy to tell, 4 lug versus 5 lug wheels.