Rebuilding a 74 Duster - Kinda...
I had a mint condition 72 mach1 Mustang Fastback a couple years ago....low mileage...pristine shape inside and out and mechanically. It had the 351C and i thought it was a DOG of an engine.
I think there are bigger and badder combo's you could go with than what you have listed in your pole....that is if money is no object.
I personally am a firm believer in a good ole 340