Japan in 1970-80 was certainly stronger after all they those new missle-battlecruisers being commissioned, however the U.S wasn't to far behind and still had the monetary and industrial power to outspend Japan completely. Not to mention those ships apparently had major technical kinks that weren't totally worked out until the 90s! The U.S still has those modified/modernized Iowa and Montana class battleships plus by 1980 the U.S still had an Aircraft Carrier advantage, though by 1970 I'd say the Japanese had the CV advantage. The Japanese could attack by the 70s, but it wouldn't work any better than it would in 1940, for all the same reasons. Sure the "Co-Prosperity" sphere was far more entrenched by 1970 but Japan still didn't have the resources to actually defeat the U.S.
I'll disagree on that point. That era's Japan would have a shot at stalemating the US advance long enough for war weariness and isolationism to force the US to the bargaining table. They're still behind US industrial might and manpower reserves, but it's not the same gulf as in the '40s. Maybe. It's at least plausible to me if you assume that ICBMs and the like don't get involved.
As in actually beating the US and seriously attacking the mainland? Still completely of of the question.