I'm not exactly sure why a set wouldn't play the hand the way he did, or something like 9

T

. Maybe if you had some read on villain that he always reraises with 88+ it would seem better to me. Anyway, you're getting a little over 2:1 on your money, so you have to have like 30% equity over his range of hands here.
Board: 9d 8h 4h
Dead:
equity win tie pots won pots tied
Hand 0: 71.265% 71.10% 00.16% 114036 259.50 { 99-88, 44, AhJh, AhTh, Ah9h, KhQh, KhJh, KhTh, QhJh, QhTh, JTs, Jh9h, Th9h, 98s, 76s }
Hand 1: 28.735% 28.57% 00.16% 45825 259.50 { 77 }
The above basically says you have 28.7% equity over that range of hands, which I think it a little ambiguous. This range includes him shoving all JT and 67 suited hands. If you break it down to only JT and 67 or hearts, your equity goes down to about 22%. I don't know, maybe you should call there if you squeeze and 3bet a fuckton, but I certainly wouldn't do it with my game or knowing the villain is quite bad.