[strictlypersonl]

The FIAs definitely ran with an increased windshield rake, but I'm not sure about the 427s. Maybe the officials figured out what was going on with the early cars.
At any rate, our FIAs have extra adjustment built into the mounting system (caged nut plates) to lay the windshield back more than our 427.
Note that things get a little flakey when the angle is way off stock: The seal at the bottom no longer works all that well.