Eric,
I have built a total of one 6.54 inch performance engines, it was a dual quad CJ-headed 410 with some heavy pistons we shaved. it did great. I have done some 5500-5700 rpm 360s, and they ran OK, but in their defense I never spent much on heads on those
However, IMHO, a longer rod doesn't do any better than any other length rod and with the slightly weaker rod, I'd likely not do it again. That being said, if I WERE to it again, I'd go zero deck with custom Racetecs or Diamonds for a real light piston so the rod and crank had a little less stress on it and still have a good valve relief then cam and compression to match use.
I am a believer that despite some minor dwell differences, in the end, a rod just connects the piston to the crank and length changes don't help much.
Now, if you just want a hot 360, long rod and cast crank longevity should be pretty good up to 6000 rpm with a good balance and light pistons, after that, the rods start to concern me first.
Of course, as with any FE, and maybe any engine, the power is in the combo, and it isn't cheap to make a small cid FE make hero power