Do you jam 4th street here for equity since you have an open ender and a low draw? I would've but I'm not sure if that's right. It seems like he has a pair of aces here most of the time and not some better low draw.
ProPokerTools Stud Hi/Lo Simulation
600,000 trials (Randomized)
6d8h7h5d 54.67% (214,076 scoops, 284,812 wins hi, 4 ties hi, 304,893 wins lo, 100 ties lo)
AL|2cAs 45.33% (157,970 scoops, 315,184 wins hi, 4 ties hi, 132,248 wins lo, 100 ties lo)
ProPokerTools Stud Hi/Lo Simulation
600,000 trials (Randomized)
6d8h7h5d 51.36% (139,859 scoops, 420,713 wins hi, 231 ties hi, 148,046 wins lo, 214 ties lo)
64|2cAs 48.64% (123,540 scoops, 179,056 wins hi, 231 ties hi, 382,729 wins lo, 214 ties lo)
Looks like we're flipping-ish against either a pair of aces or a seminaked low draw. But we'll probably have position on later streets. So I don't see a problem with raising, especially if we can benefit from some initiative. We don't exactly have a bluff-catcher, so we shouldn't benefit much from keeping his range wider and aggression up.