My frame has a slight arch across the top 12 3/4" top to bottom at the center.13" top to bottom at the wiper arm .13 3/4"at the end from the top to the lowest point of the curve.It seems 1/2" short all across the bottom.
The top arch differs from your description.The frame I have follows the cab line from the inside but not on the outside.
Thanks Todd (backn37)
