Well, its a matter of choice I guess, so if it were me... and since its a Mustang, I would go with the Cleveland. I had a Mustang once with the Cleveland and it would scream. Made my girlfriend scream a little too lol. All those engines have potential, but I think the Cleveland captures a little of both worlds.
I love it when people do things right
Unfortunetly I dont always do that lol
I've never done the engine change, but putting a 429/460 into a Mustang is quite a squeeze into the 1969 Mustang's engine compartment. Tight fit between the shock towers. The Cleveland drops in with room to spair, oem parts.
For 460-to-Mustang motor mounts, headers, radiator, etc, click below: