Doors and Windows - Confused Fins

Looking to install my first "fin" window (vinyl) in an old place before beginning an addition which will use many more.

Looking over the web, found many conflicts over how to install a "fin" window....

Flashing.....is the Grace Vycor over the screwed/nailed fins enough or does one put it over the top edge of the frame?

Sites said nail every 3" to 7"......Does one nail every slot or every (how many?) inches.....

What nails should I use? Several sites say use roofing or stainless steel nails......A fellow who should know told me that Florida Building Code requires length of screws 2" minimum or nails at 2 1/2" minimum. Can't find roofing nails that long or any stainless at the home centers..... Want nails because of the lower head profile than screws making trim over the fins much easier.

Thanks,,,,

Caulk under fins, 2" roofing nails should be easily available, nail every slot/hole. Then adhesive flashing over fins starting from the bottom, sides top. Top end of top piece should go under the housewrap. And there should be metal flashing over the top and under the housewrap.

Well, if 2" nails won't meet requirements, you can use flat head screws, which should compress the fin enough to sit flush. Deck screws come to mind? Or exterior grade screws...basically drywall screws with a zinc coating.

If you are in Florida, I would contact the local building department for answers. I spent some time just now researching. The window company has to be approved by the State for the useage. The manufacturer's installation instructions have to be followed. In some cases the window has to be inspected after installation. Be safe, GBR