Party 750k cripple-me hand

[Gamblor]

180 left, I have about 21k. Avg. is 17k I'm in no trouble.

3 orbits into a new table, I haven't played a hand. I'm in the cutoff with T8s and open raise 3BB to 4500. the SB (with 17000) minireraises to 7500. I call.

Flop comes T64, BB bets 5000 of his remaining 9500. I push.

My real question is the preflop action, but the flop push is also up for debate.