You're confusing the 2 V10's. The V10 from Oz's post is a 5.4 with 2 extra cylinders, the 6.8 Triton V10 out of the F250/350 (5400cc/8 cylinders = 675cc per cylinder. 10 cylinders = 6750cc or 6.8 litres). The Boss 351 V10 is an experimential short deck block designed to fit in the Mustang with little to no modifications. They're two completely different engines.
Like Oz said, the Aussie Stang did require major mods because it's a tall deck block.
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