Places to get groups

[Gustoo]

Level 39 you can either be still getting EXP from festering hags, or from spectres at their various locations with the highest level ones being the plane of fear entrance area in feerot.

Then you can venture into Lguk which is good exp solo also.

Otherwise toxigens advice to find an enchy is the best. Its an insane duo, the cleric means the pet doesn't rob EXP anymore, it just goes to the cleric so its basically a free upgrade, and your HP Buffs keep the enchanter from being killed, and you can CH the enchanter pet so you can keep the ideal pet for as long as you want.