Plectron,
I agree with 411A and rottenlungs.
But also: if you remove that heavy centre engine and its mounting structure, you push the C of G way forward. So you either have to move the wings forward (impracticable), or extend the rear fuselage. The larger-diameter engines would probably necessitate lengthening of the landing gear.
There are already two formidable big-twins on the market.
Chris