Fantastic Fan in place of AC

[Stork]

Here is my issue, I want to put a Fantastic Fan in my 28' Argosy. The previous owner had removed the AC so the 14" square hole awaits, and the extra bit of light in the kitchen area would be great. The problem is the edge facing the front will require drilling into the support rail. If I attempt this will I be able to screw into the rail? Also being there is no flex at that point I may also have an issue with the fact that the new vent is perfectly flat and the roof has a curve. Has anyone else here attempted this? Any advice would be awesome!

Thanks!

[CRH]

If I recall correctly, when I installed a new FF one end of it was right against a support rail. It caused me no problems.

[HowieE]

As for the curve that is the same problem when installing a newer AC unit. They use closed cell foam to make the seal and account for the curve.

Foam to fill the gap and RTV to ensure a seal to the roof.