Factory intake variations?

[GS -]

I've noticed in some pictures of our intakes there appears to be some variations in the STOCK design. The runners on some are shorter and do not reach all the way to the bellypan and the openings inside are angled up closer to the TB. The same can be said about the internal divider which runs the length of the manifold. Some intakes have an aluminum bladder built into this divider, some do not. Anyone noticed this?. This may explain why some stock trucks are faster than others with just a few mods or I'm bonkers. If you get a chance, check your intake with a flashlight.