Yeah i'm with that as well. Pretty plausible when you start thinking about all the advances thats been made. Specialist cranks (alloy and what not), Alloy rods, pistons. And then on to the head with roller rockers, modified rockers, custom dual (or triple) valve springs, oversized valves. Upping the compression, better fuel, better fuel control.
Yadda yadda yadda
Years ago i got a book from the library, David Vizard was the author, and one of the things he wrote about was for the under 1litre motor (850cc or something like that) was of modifying the intake ports - filling in, or blocking, the ports and moving them to almost vertical. It was so that the air/fuel mix had a straight shot from the carby to the valve and into the cylinder without a dog-leg.
And the bitch side of it is that all the David Vizard books have been pulled from the shelves (re-read that as "stolen")