no, the 4-holers will not take a 700 rear base. i think the fronts are interchangeable.
the rear bridge on a 7 is significantly smaller than a 700. therefore, the holes are closer together. also, the rear base for a m7 is shaped differently ('built-up') so that it can get the scope centered. a one-piece rem 700 base will go onto a rem m7, but don't do it. you will bend the base really bad, stress the receiver, and then either listen to the 'smith laugh at you when he discovers the mistaken base, or decide the gun won't group, and sell it at a huge loss...
in fact, that is how i came across my first m7... guy said it wouldn't group at all. nothing worked, and handloads didn't do well either. sold it to me for $100 w/ rings and bases (no scope). i shjot it, and thought maybe i'd been 'taken', but before getting bent, i wanted to try a few things... so, i pulled the scope and rings... then, had to wrestle w/ the base forever, after a couple of days of wrestling w/ the bases, i finally got the rear screw out, and the rear of the base just popped up (back to level). further inspection revealed it was a m700 base. so, i corrected the base problem, and put the gun back together, and had a bona fide shooter... so, i glass bedded the rifle, and worked the trigger over, and voila! i have a light, compact rifle that shoots far better than it should.
so, yeah, the base does matter.