I mean Ford is going from being a Buffet to a Chipotle. I'm not suggesting a million part combos, but maybe just offering those upgrades for known weak points.
Ford goes "We want to offer a forged rod/piston/crank package", suppliers bid to Ford, what they can fill the order at, like how Walmart operates. It's not really pick from a ton of options, its a custom illusion really. You want stock pistons or this upgraded brand we have sourced? You going to pay extra for steak or nah? 3rd party manufacturers will be held to the same warranty, Ford deems valid.
Sort the assembly line into divisions. "This car has the upgraded 6R60, it kicks out the line briefly and goes to the SVT line, slips back in line, on to the next division. It can be done extremely efficiently.
------| Motor/Trans |--------| Suspension |------etc
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I guess Dodge did do something similar with the customizeable vipers recently.
Ever heard of option cost?