when the right play looks like a donkey play

originally posted on MTT area, but after a good suggestion, posted here as well (as this is actually a STT...) Payout is 3rd $50, 2nd $150, 1st $300.

I caught a lot of crap for this one, but i think it was the optimal play. Down to four (2 pay, 3 gets money back) at live tourney. blinds 200-400. I had been playing selectively aggressive, picking blinds up slightly higher than the rest of the table, so that they wouldnt play back. The last pot I won with a continuation bet on a paired board. Table was fairly tight, but didnt want them to not give me credit for a hand, so i wasnt overdoing it.

BB was a good player. We had clashed early on, and i had made him back down. He had just doubled up and was 2nd in chips to me.

Hero, button, (7100) raises to 900 with 7d 4s.
Villain, BB, (4500) calls 500 more. (seems like a funny amount to raise, but this slightly above min raise was table standard, and was working. Besides, a larger raise would pot commit me before I knew what was what.)

Pot 2000.

Flop 7c 3h 3c.
BB checks, I bet 1000. BB min-CR's to 2000. Pot 5000. I have 5200 left. I put him on PP, down to 55, or two high clubs as most likely holdings.

A clear all in or fold here, right? Though I could legitimatelly be in really bad shape, I dont think hes giving me much credit for a hand with this flop, and may think A high is best. What do you guys do?