[AsydRayne]

With zero fold equity, you need 45% equity to shove the flop. You don't have it.
Board: 8h Ad 7d
Dead:

equity win tie pots won pots tied
Hand 0: 39.158% 39.11% 00.05% 6969 9.00 { 6d5d }
Hand 1: 60.842% 60.79% 00.05% 10833 9.00 { 88-77, A8s-A7s, KdQd, Kd8d, JdTd, Td9d, 9d8d, 87s }

To make the turn call, you need 32% equity, which, assuming he bets pot with the exact same range on the turn, you do have.

Board: 8h Ad 7d 5h
Dead:

equity win tie pots won pots tied
Hand 0: 38.258% 38.26% 00.00% 303 0.00 { 6d5d }
Hand 1: 61.742% 61.74% 00.00% 489 0.00 { 88-77, A8s-A7s, KdQd, Kd8d, JdTd, Td9d, 9d8d, 87s }

If he slows down with some two pair and drawing hands you don't have the equity to make the call.