Guys, guys, guys.
The poster asked for a suggestion. Though he disclosed info about the nature of his injury, NONE of us are in any position to tell him what not to do.
He said he doesn’t want to do conventional deads because they hurt/are hurting him.
Now, it’s fine to say “I’d personally stay away from GMs because they stress the back more than deadlifts.”
But you have no way of knowing whether they are actually going to hurt him in the same way. Everyone uses different form, and frankly I suspect he can figure it out for himself.
To the original poster: Go with your instinct, if you’re smart enough to figure out deads aren’t good, you should be able to figure out from this generously varied thread what is.
I just despise internet diagnoses; though the guy asked for suggestions, there is no need to say “NEVER DO EXERCISE X IF YOU CAN’T DO DEADLIFTS.” For all we know, Good Morning squats with chains may be his freakin’ magic bullet. The point is, try these exercises safely with a safe load, knowing your form etc, and think for yourself.
Good luck.