With no BB, push into Bigstack for 150chips with T8s has to be marginal at best.

Big stack has no immediate inducement to call as he has no chips in play. Your winning the hand has no effect on him or the game. The status quo is maintained if he folds. In effect it is a "free hand".

Better from your point of view to look at the risk you're taking for just 150 chips. T8s is a middling hand, what will the BS call with ? I doubt he will be loose at all for the reasons I've given above.

You don't want a call, and big stack has little reason to make one unless he has a holding of some sort. Still, all this for 150 chips. I don't know.