Doesnt the firewall already have one big hole in the center towerds the top? I am building the 60 so mabey its different. Also, I dont know if your kit came with it, but my 60 kit came with fiberglass cloth and i just wanted to say dont use it, its very thin and brittle compared to the other fb cloth iv used. I think i have Great Planes cloth on my avistar and its very good. Epoxy it dont CA. Just my 2 cents.

NMTR13