Of course you can't know what they have while you're playing the hand, but you're a pretty big dog vs their specific hands.
http://twodimes.net/h/?z=11494639
pokenum -o jc jd 4s 5d - as 3s kh 7c - 8s 9s 6d td -- 7s 6s 3c
Omaha Hi: 666 enumerated boards containing 7s 6s 3c
cards win %win lose %lose tie %tie EV
4s Jc Jd 5d 142 21.32 524 78.68 0 0.00 0.213
As 3s 7c Kh 237 35.59 429 64.41 0 0.00 0.356
9s 8s Td 6d 287 43.09 379 56.91 0 0.00 0.431
Change the hand to your left from nut flush draw to a set (just as likely considering the action) and you're even a bigger dog.
http://twodimes.net/h/?z=11494640
pokenum -o jc jd 4s 5d - as 7h kh 7c - 8s 9s 6d td -- 7s 6s 3c
Omaha Hi: 666 enumerated boards containing 7s 6s 3c
cards win %win lose %lose tie %tie EV
4s Jc Jd 5d 103 15.47 563 84.53 0 0.00 0.155
As 7c Kh 7h 200 30.03 466 69.97 0 0.00 0.300
9s 8s Td 6d 363 54.50 303 45.50 0 0.00 0.545
That kind of actions OTF in PLO usually indicate bigger draws with redraws, so your low str8 with no redraws goes way down in value.
I'd probably fold a hand this weak pre, unless I had nits in the blinds. But nits don't tend to play PLO.