Probably not going to work. I would recommend selling the van very cheap... to me
Actually, i really am looking to buy the 1500 chev AWD for a conversion. For me, i think it will be fine. I'll just take care to build light and try not to pack a crazy amount of stuff. Couldn't say it will be ok for everyone.
I would imagine that if you did run over-weight, the only thing that you'd need to be really concerned about would be brakes and transmission. You can do things to beef up the suspension if necessary. Then again, i don't know much about it.
Search for posts by Accrete and Zuren. They both are running that van.