Just Bought a 360
Well, if I were to replace my J heads, it would be with a set of 308's or Magnum heads. As far as factory stock heads go. I have both sets and just await the forth coming spring to fool around with them.
I'm currently screwing around with a 318. And will test several heads on top, just to see and play with. No other reason than that. Just spend money and burn rubber and gas. Oh! And then post about it.
Anyway, with those pistons sitting at zero deck height, think about a slightly thicker gasket to make pump gas a bit easier to run without retarding the timing to do so.
Fel-Pro has gaskets @ .054 and then theres Cometic in what ever you spec to them. A slight shave of the ratio would be good IMO for most case build on the street.