Thanks Brian...if only I would have taken the time re-read the thread....my bad. OK, if this isn't a super rare, Big Block or Z28 car...(Something that they didn't make to many of) then what you can do to enlarge a gap on your doors or your deck lid is to take a stainless steel welding rod...take off the coating and weld it to the lip or outside edge of the deck lid...these rods can be 1/8 of an inch wide when the coating is off and if you weld it onto both sides of the deck lid it will give you and extra 1/4 inch of deck lid to work with. After it's welded on, install the lid, adjusting it to give you your best fit. Grind away whatever you need to give you the gap you want, apply a little filler on the welds (both top and bottom of the deck lid), block, prime, block and paint.
If this is a super rare 70 Camaro, I would advise to have the quarters re-installed correctly to get your gaps. I've done this on several custom builds (usually pre-war cars), because they are customs it doesn't matter, gaps are what's more important than originality.
I hope this helps.