First off those heads are not 428's. They are early FE heads for a 332-352 1958 models. They just have the CJ Valve sizes in them. Don't get me wrong they are probably good heads and will work fine for a nice build up. They head volume is 69.0 - 72.0. They will net a little more compression ratio but under the right circumstances that could be a good thing. One other thing I would look into is getting hardened valve seats put in to those heads.

For the price the guy wants for the heads I would look into pricing on fixing your old ones. Just Some Ideas.

Scott