'assembly' updating - what consitutes an engine again?

[shwah]

OK - We are all aware that under the update/backdate rule, when it comes to motors the assembly is considered to be the long block with the head and bottom end together.

What about the other components?

For instance intake manifold on a later motor has an additional mounting boss for a decorative cover - or additional support for a fuel rail. Does the long block = throttle plate to exhaust port, or could you use either part (provided they are otherwise identical)?

Or in the case that brought this question to mind. For my car early motors came with cast aluminum flanges (the part that bolts to the block or head with a 'hose barb') for cooling hose attachment, and later ones used plastic here. I have integrated my gauge senders into the older style aluminum flanges. Do I need to replace this with the plastic parts when I put the later Digifant motor in?

I can't convince myself that any of this makes any difference, other than I already have parts to use in one case.

Thoughts?