Huge draws - push, raise, or just call?

[yvesaint]

10+1 STT on Prima.

Hero: 990
Villain: 1400

Blinds are 20/40, I'm in the BB with Ac4s, it's folded to the SB, who completes. I check.

Flop: 6c 5c 3c

Villain bets 120 into the pot of 80. Hero... ? No reads, seems Villain has been playing textbook up until this oversized bet.

[Bigwig]

I push here. I think your A outs might be good, too. That would give you 18 outs. The problem with calling this overbet is that you're either going to be facing another huge overbet on the turn, or he's going to shut it down if your draw hits.