Good example is my old '71 340 Cuda, best I could do with a stock-ish motor/chassis was 12.39, sold it and new owner put a quite healthy but nothing outrageous all iron 440 in it and ran 10.90's once he put my old 4200 verter in it.
Ya, 100 more of CID will often have that effect on ET's. Love my 340 for sure! But as Dad (A guy that had a big block in every vehicle he bought after about 1960) always said, no replacement for displacement.
