Thanks for saving the site.
What you didn't get from the site, mostly because they are notes, is the fact that
I am the one who did the mods and created the web page. I never got around to making a proper page, but wanted the info to be available when necessary.
I too am 6'3" and can tell you that two inches back is plenty, especially if you dropped the floor pans an inch or so as found in the first link. The tracks I made are good for 3" back, but that is not needed. With the dropped riser and the tracks set back, I am straight armed when shifting into 2nd or 4th, which is most forward and near the dash. I am almost straight armed with the steering wheel, like an early European performance car. I need to lean forward (actually quite a bit) in order to turn on the headlights, wipers, or adjust the volume of the radio. I did not try the extending the seat tracks first before cutting the pans. Cutting the pan allows more than enough roof clearance for me to wear a helmet. It also makes me look like a short kid driving the car to the outside world.
Anyways, the instructions given work great with my 6' 3" frame and no other mods are needed and in my case, none are planned. As far as seeing the tracks, they quickly become invisible in a black interior, especially when the new paint lost its gloss. Remember you can see the stock gray tracks too.
When/if I decide to sell my car later, all I really need to do is remove the tracks and bolt the seats back into the original position. Hopefully a new owner won't mind the lowered pan. I can use the tracks in my "next" project . . . . . .
Gee, sorry if the post sounds comes off sounding defensive, it wasn't meant to be--I am in a rush to head to work and typing as fast as I can. . . . .
Good Luck to all!!!