Yes, the Galaxie on BaT is why I’m asking. It’s a C6 block with D2 heads. Steve Christ references D2 heads on non-air 428s but the date codes don’t add up. The seller also said it had dished pistons which threw up another red flag for me. If it is a stationary power unit it would be a ribbed block no?
The ribs on a FE/FT block are simply a matter of time, and which foundry they were cast at - the ribs were on DIF ( Dearborn Iron Foundry ) cast blocks, and started sometime around the 1971 calendar year until the end of DIF production in the mid '70's. So like Jay said, the blocks could be either ribbed or plain.
There are a few mistakes, and more commonly omissions, in the Steve Christ book, and all the subsequent published & online FE casting lists that copied it. It's one of the biggest problems we fight with people trying to figure out their FE/FT, just take it's info as kind of a helpful first step, and not gospel.