[twoblacknines]

I'd probably fold 43o preflop if you don't want to continue with it postflop when you hit trips.

I don't see him having a boat and playing it that hard, and I don't see any 3's he could really have except possibly A3s.

However, he is making a strong raise into a big multiway pot. Definately puts you in a tough position now, which is why I think you should be folding 43o preflop to begin with.