No, no... at 40, get thee to the Ivory Tower pit to do the "Under the Shadow of the Ivory Tower" quest. You'll make a mint. It's only of the only quests actually worth doin in the game.
Acutally, that's not such a bad idea - the non-resisting mobs in the north half might be one-shot using a +INT tat/demon set/homu. I'm not sure! But they both got bonus exp (one for being a stunner, one for being a nuker), that's pretty sweet - might work all the way up to your 44 skillset (at 46, one of them turns light blue).
However, AI is more tightly packed in terms of spawn, so the experience per time is likely better - and if you're lucky the quest rewards there can be pretty nice too.
You can go 40-44 in the IT Pit. Then move a little north to Bugbears and Formors, 44-47ish. Then move north again and fight the Basilisks, 47-52ish. Then you hit b-grade and can move to the front of the Cemetery.
Like someone else said, get +INT and +WIT tattoos, makes your life so much easier.
instead of moveing n. to the basalisks go to dragon valley and do the quest to kill skeltons. There is a nice quest at the entrance that gets u a lot of goodies. like 5 ea c and a ton of mats. You can do this quest until about 54ish. Or until you got all the rewards (u need to turn in 300+ items to get the good rewards)