any benefit to swapping heads?

All this back and forth over Cams, Cr, ICL, valves, port velocity, TM,,blah, blah, blah
While the whole combo is choked by the stock cast iron manifolds.

All the proposed "gains" of the various witches brew of "mods" simply pail in comparison to a decent set of equal length, 1-5/8" headers and take significantly more time and money.