Our IC RE's factory specifications read 42'2" with 303" wheelbase. 90 passengers. I guess if I added the hitch and mirrors, idk, add a foot.
We measured from the interior of the windshield to the interior of the rear glass at 41'9", using a 100' tape.
Dont know where to measure to compare FE vs RE, the build space goes well beyond the last window, 36" wide stairs yet flat floor to the dash. About 38' flat floor + 10" seat? Behind the stairs + rear seat, we measured 36'.
I have noticed that the FEs have additional bus to the right of the entry door, maybe some of the length is out front?
The additional 90"w x 48"h x 30"d space over the engine is a horizontal closet.