[Colonel Ingus]

I assume you are playing O8, and not PLO, since you don't mention the sizes of the bets and stacks. Given than, I would also assume that the flop was checked around. On a flop of 498, that would be highly unusual in most games I've played. If there was a bet on the flop, I would immediately toss my hand in the muck, since there are two low cards on the board and you don't have enough equity to continue.

Okay so you get lucky and see a free turn which gives you the current nut hi. You bet out and get three callers, one, two, or all three of whom most likely has A2xx, or even A3xx. Since there was no flop bet, the xx have to be absolute trash, or the players are weak-tight. A 67xx might call here, as would a 7Txx, and a QJxx. You would expect a push on the flop from A2 or A3 plus a set, two pair, straight draw, flush draw, or even 1 pair plus some additional wheel cards, or high cards. You might even see a push on the flop from a hand like 99HH. So we've ruled out the above hands with some safety given flop actions.

Now on the turn, you would definitely expect a raise by someone with a hand like A2TT. You may or may not see a raise by someone with low draw + T4, T8, or T9. If the villain is normally agg on the turn, I would rule these out if they just call. If not, I would have to proceed with caution.

On the river, there are about 6BB in the pot given your situation. The real question here is whether to bet and fold to a raise, or check/call. The primary determining factor of whether or not to bet/fold, or check/call, is pot size. I think check/folding is too weak as you would have 7 to 1 odds for a likely scoop. If you bet out, all the low draws without much else will fold. Hands that you have beat that might call are someone who has the same hand as you (JQxx), trips, two understraights, and even AAxx. We've ruled out most of the hands that have you beat, unless your opponents have been playing tricky. So the only hand you would really be worried about a boat someone backed into. Having said that, I have been raised on the river in these situations, and I don't mind throwing my hand away since the pot is small. If the pot were larger, you definitely want to show down your hand, so I would lean towards check/calling.

On a final note, if you have reads on your opponents, the correct play may be something entirely different.

Just my two cents. I could be completely wrong. Hope it helps.