can i use a regular deadlift grip (not a reverse grip)
on those kind of deadlift most people i see do those do a reverse grip to do this
and i really want to do some of those deadlift for my hamstrings (since stiff leg deadlift kills my lower back due to the position i need to have when i do the movement

Why would you not be able to use a normal grip?

The reason people use mixed grip is to prevent the bar from rolling=more stable grip.

this, you can use whatever grip works for you on any deadlift stance

alright thanks a lot for info i just wanted to be sure since deadlift is one of the exercice that you can injure yourself really fast if you dont do it right

Double overhand chalk raw sumo crew, some reps the bar slips into my fingertips cuz no grip on the bar (it's smooth where I grip)

You should use the conventional pronated grip for as long as possible. Use chalk if need be. Grip strength is part of the lift.

try adding some weight on the bar and using a double overhand grip.

I pulled 315 double over, that was 2x bw for.me, and just pulled 295x5 this morning

try adding some weight, double over isn't going to get you into 3x bw and 4x bw.

yes it will.

you build grip strength over time.

you don't build grip strength by doing reverse grip only.