At first I thought this is the easiest x/f in the world.. but oh wait, this is not PLO forum, never mind.
In NL this river is pretty much a blank. In a sense that's unfortunate for us, as we can't really expect him to bluff with missed draws when we check to him. If he has us beat it doesn't matter either way; if we bet he calls/jams, if we check and he jams we have to call.
That said, our river decision pretty much boils down to what is the most +EV option vs Jx and QT/KT type hands. Tx will almost always check back this river, and Jx might check back a decent amount of time too. Tx probably folds to our jam, and Jx probably won't. Given that there are more Jx combos than Tx (we block Tx, and he probably won't bet/call turn without some draw), I think anywhere between 420 to jam is fine and probably won't matter much in long run.
Btw b/f is not an option with this stack size.