can i put a V8 904 bell housing on a V6 904 and bolt it up to a 318?

They dont have bellhousings really. One piece transmission-bellhousing like a chevy or ford. So, that sucks. Craigslist. Small block mopar transmission time. Is it your only car?
Otherwise I would pull the trans and rebuild it. You can probably find a fellow mopar guy down there that can lend you some knowledge and possibly a helping hand. If I were living in your area I would help you out probably.