I don't really understand why we feel the need to bluff here. He very rarely folds a better hand and we're good against the 75% of his range that you're trying to fold out.

I'd much rather call here and evaluate the turn based on what you know of this player, and expect to be able to get to showdown a lot.

I know you are worried about scary looking cards coming off, but it's not a reason to stick more money in than we need to with a hand that only gets action when behind and never folds out better. If he's going to fold this much I'd call here with 77 and bluff raise a ton with hands that don't have like 70% equity vs his range.