Just got my first Firebird this weekend - a '68 Firebird 400 (currently with BBC engine), 4 sp, etc. Was looking for the build sheet and trying to get the back seat out so I could look underneath. Wasn't coming out. Tried to pull the top of the seat back and felt a lever - pulled on the lever and the seat folded down. Guess it's a good news, bad news thing - couldn't find the build sheet, but did find an option that I didn't realize that I had. Curious to know - is this a rare option?