Opinions welcome

I'll chime in that if it's just an occasional cruiser, drums and the single MC will be fine. Personally, I would at least swap to the dual MC as most people at car shows would never know it wasn't original. Back when I had my first Valiant ('71) with a 340 and did a lot of "spirited" driving, I knew that the 9" drums just didn't cut it. I swapped to disc/dual MC/ prop valve (off the '68 'cuda the 340 came out of) and never looked back.