Trying to address all your points so bare with me...
The challenger doesn't sell as just as you think it does. It is nowhere near mustang sales which is the reason why dodge always has hp per dollar discounts . How many times have you seen Ford have 0% financing or thousands off msrp for a Shelby car? It isn't working for does like you think it is, they have to give those away to move them off the lot.
All NA power is not equal, making more power in the coyote is not the same as having a voodoo motor. The FPC motor is special and ppl buy the GT350 for that alone. So no adding more power to a coyote based motor does not make It more like a GT350.
How saying " why aren't we seeing more GT's and GT350 bought to mod"? Well first of all we are seeing a ton of ppl slapping a SC on the coyote motors, you don't see more of the GT350 because of the cost . The mustang crowd is bang for buck so if you have a car like a mustang with a SC on it from the factory ppl will no doubt buy that before a GT500. It will hurt the GT500 sales without question. There is a reason why the only SC motor Ford has build has been the Cobra/GT500.
