340 Help

I have a 1973 340 I want to put into my 74 Duster behind a 904 transmission and I wanted to check with you guys before I bought some wrong parts.

This is an externally balanced, cast crank engine correct? (1973)

So I could use the B&M flexplate with the "bite" out of it?
How about a convertor? As long as its a non-lockup and fits a 904 it's OK?

Thanks for your help, I really don't want to screw this up.