Big Block into 1970 Swinger

I am looking for a bell housing for my dart, was /6 and looking at a 413manual transmission. Mostly always been a small block guy, any one with spare pieces or maybe just good advice as to what to look for or avoid? received some good tips so far, some work ahead but that is OK, I think I will need the bell housing so I can do some mock up. I would like advice, that is always cheap, some cheap parts would be OK as well, but I understand reality also.