bb or sb for my 72 dart swinger

It's much easier to put a small block in one than a big block. With a big block, there isn't room tor the brake booster and power steering can be done but it''s tight. Alot of these cars came from the factory with small blocks, so they are easier to fit and there are more parts available for them. I am building a 1970 Duster and have had this dilemma as well. I have a fresh 450 hp 440 in my garage that was for a truck project that never came to be and toyed with the idea, but have a 340 that I am going to rebuild instead. The big block adds some extra weight to the front end as well, which will not make the handling any better. I know alot of people go the big block route in A bodies and love it. JMO.