[Dean]

Technically, it is about documentation, not actual parts. If from a manufacturer part perspective, the part is the same, it is the same, no matter how many components or even the single part is different. Even if there is a part number change, but you can provide documentation of that change and that the replacement part number is an the official replacement part for the original part, it is OK.

Many long or short blocks from manufacturers provided for warranty or non-warranty are "rebuilds" anyway and may or may not contain all new internals. So if I order an '07 long block, it is entirely possible that the serial number on the block may be an 04 serial number with '05 parts that they rebuilt it with.

None of that changes the fact that the part number for the replacement long block for an '07 theoretically is the same as that for an '04.

My guess is that the VF43 will become either "an" official replacement part, or "the" official replacement part for the VF39 for all years at which it really becomes a moot point.