[barongreenback]

I think you get called by A3 and 56 here (+53 maybe) although he'll bet these if you check. You fear K3, 77, 44. Since you've played with him for a bit you may be able to exclude 77 and 44, if he raises these preflop, and he may not be playing K3 UTG. I know you're deep but it may be that you really like to get raised here. It really depends on the how rational you know him to be but insanity is suprisingly possible.

There shouldn't be many hands he could hold that he wants to bluff with. I always surprised what people will crying call a big bet with on the river. Give them the chance to make a mistake.

I check/call or bet the flop to avoid giving my hand away and give a chance for someone to hit a straight but this hand is vulnerable so maybe that's not right. It also keeps the pot smaller which you may want.

James