Will a 77 Charger 360 fit in a 65 Valiant Slant Six Painlessly?

There's no way for anyone to answer that, because we don't know YOUR skill level. I've been workin on cars since 1974 and I find it safe to say that really nothing on a Mopar is painless. Will it fit? Yup. It's a bolt in swap. Can YOU do it? Chit if I know.