The Ford GT has almost no common parts with any other Car period, Ford or other wise, Internal Engine Parts mostly. Almost everything was Custom made specific for that Car. That means it’s not the Engine that cost that extra $100.000.00. The GT500 has 70% Commonality with the Mustang GT mostly body parts, Glass ECT... The Ford GT Replacement motors are $33K the GT500s are about $16K the 4.6 Stroked to 5.0 are around $9K so the Aluminum Block Don’t Cost all that much more. To not put it in the GT500s is just not a good marketing scheme.
What are the chances of Ford putting a Wolf in a Sheep’s skin in a 09 mustang? IE. A 5.4 Aluminum Block/Blower 550hp and 500tq motor Upgraded Brakes, Tranny, Rear-end, Springs Ect. Basically our cars in a Pony Package Body.