Your a pretty tall feller and so am wondering why your built up the floor and pedals. I am only 5'6" and I built mine up so I could have the seat back farther so steering wheel wasn't in my face. Also I don't have power seats and I feel the seat is a bit high. So I built up the floor with a couple of pieces of carpet under the mat. You must have felt the floor was a bit low also to build it up 3"??
3" made the distance from the floor to the top of the seat about the same as my work van.
I do long runs when I use my PC 10-15 hours, so its good to be comfortable!
Measure your other vehicles seat to floor to pedals, and see what ya get? I only did my van, I am gonna check street cars and see what I can learn.