Im just awaiting the postcard in the mail about the class action lawsuit of people waiting 3 years for these parts and the liters of oil I have poured into it just to keep it full.
How are they able to keep making new trucks without supplying everyone the exact same engine covers for the existing ones? the 3.5 Eco didnt change
That is not true, the valve cover in question was a design produced from 2017-2020. In 2021 something changed and the part # is different. As this part is no longer a part needed for vehicle production Ford is relying on suppliers to fill the orders. If this was a currently used item on the assembly line Ford could divert parts to fill orders. Not that they would, nothing gets in the way of production. But they could.
Also, due to modern vehicle design the valve covers are an integral part of the emissions system ( pcv system) and have to go through EPA/CARB approval if manufactured by the aftermarket. (oem have already gone through the process)
I assume that there were lets say 50 injection molding machines making this valve cover when it was used on current production vehicles back in 2017-2020, but then the design changed and they switched the machines over to the new design. leaving a couple to produce replacement parts and the machines are broken down or they can not find the man power to staff the machines.
I have been fighting a similar issue in my shop with a 2017 F150 2.7 ecoboost. The oil pan is non-existent has been here for 10 months. the oil pan designed changed in 2018. Ford just released a TSB that they are waiting for EPA approval to retrofit 2015-2017 2.7 ecoboost engines with the 2018-current design. If approved (don't know why it wouldn't be) the replacement of the oil pan WILL REQUIRE the replacement of both valve covers also because on the 2.7 the oil pan is considered part of the PCV system and has to work in conjunction with the correct valve covers.
Vehicles ain't getting simpler they are getting more complex, and stuff like this is why I don't see the aftermarket making much more than brakes and tie rods in the future.