Check out my car and talk to me about 318/340 swap

318willrun said
Make sure of the year on the 340..... Some were externally balanced and you'd have to accommodate for that. Your 318 would be neutral balanced, so the converter would be wrong for an externally balanced 340.

(Some) Late ‘72 & all of ‘73

moparmat2000 said
72 I think it was when cast crank 340s came out, but at this point in time its anybodies guess what crank is in there now until you pull it apart.

IDK why they changed the balance over for the 1 year only 340, but very late ‘72’s were also done this “odd” way.