For 8 reps? I don't care about weight or reps unless I am boasting or doing a strength feat (for me). I lose count but when I was a permabulker i did 6 x 80kg whatever that is in lbs with half decent form (@115kg). You cannot do strict curls when it approaches that % bodyweight or over unless you have tendons of silicon carbide and some weird way to avoid gravity.
Got better gains super setting lower weight preacher curls + standing curls, reps not counted, with 50kg or so on bar for high volume without breaks - and no joint pain.