Will this gas cap fit with out modifying the sheet metal you think?

The base has holes for a 5 screw attachment, I was just curious about diameter, etc....

http://cgi.ebay.com/ebaymotors/1971-72-73-Mustang-Mach-1-Eleanor-Pop-Open-Gas-Cap-NOS_W0QQcmdZViewItemQQcategoryZ140708QQihZ019QQite mZ290134091521QQrdZ1QQsspagenameZWDVW