Depends on the qualitly of oil, a yamalube for example you should run about 20-32:1, higher quality oils Id run 32-40:1 (klotz, maxima) This isnt stamped, just a suggestion.
I use bel ray gearsaver for about 12-15 hours in the tranny.
I dont know what JP2 is, but once you run synthetic, your only supposed to run synthetic.