So outta curiosity chopped the old vs new. Double and triple-checked the dimensions to make sure they're right, and it's somewhat weird, surprising.
I swear the FT86-II concept wheelbase is shorter, that's why I thought the concept was bigger than they said. If you notice, the original concept has the rear wheel that's an inch or so further back. If I were to match the wheelbases of the two, then the 18" wheels on the FT86II concept would be the same size as the 19" on the first, so I don't think that's right. How it's sized now, the wheel sizes are about proportional.
Also interesting to note, the hood looks longer mainly because the front windshield is placed further back, thus accentuating the hood length and short overhang. The added length mainly comes from the pointy ground effects up front and the chunkier bumper to the rear. So in actuality it seems like the front overhang is largely unchanged.
You can also notice the difference in C-pillar shape here. I purposely just uncovered specific portions since they look so similar overlapped.