stud hi/lo odds question. yes, i'm serious.

[fisherman112]

a few friend of mine play mixed games from time to time and i got involved in a large stud 8ob pot with an interesting 6th street decision.

i had started out with a monster draw A [img]/images/graemlins/club.gif[/img]4 [img]/images/graemlins/club.gif[/img]5 [img]/images/graemlins/club.gif[/img]2 [img]/images/graemlins/diamond.gif[/img], caught air on 5th and made an 8 low on 6th. my friend raised my bet with 4 low cards showing. i was positive he had 6 low cards and 2 pair. i have, best case, 3 outs to the high, how big does the pot have to be for it to be +EV to call, hope he whiffs on his low draw 7th st and we split the pot? assume im always showing it down.