[olddog]

A 428 bored 0.040 over gives 4.170 bore which would require a 4.41 stroke to get to 482 cid.

A 0.060 over bore would require a 4.375 stroke. This seems plausable to me, if you off set gound a 4.25 crank, I think you could get there.

Not that I have an opinion on the advertiser, just trying to see how he could get there.