If you're using the stock battery hold down then it will bow the top.
I have had the fake Autolite cover for years now and have a maintance free NAPA battery under it. The battery top is completely flat. I peeled all the NAPA stickers off the sides so it's just a black battery now and it blends well with the fake top.
__________________ 1968 Mustang coupe, Acapulco Blue, 289 2v, C-4, Power Steering.
Hopefully a 1969 convertible or Sportsroof (non Mach or Boss) for next Mustang project 
Trying to find my father's 1973 Mustang Grande he bought brand new. 3F04F126773 last known registration and title was in New Jersey, 1982. | 
Autolite Battery Top Cover 
