I have been searching for a 1968 Impala Convertible frame for a few months now and haven't been able to find anything. I have been searching for 65-69 gm convertible frame but still no luck. I was wondering what the differences were between a 2 door hardtop and a convert frame were besides a boxed in frame. Would it be best for me to wait til I find a natural convertible frame or should I go with a coupe frame and box it in? Any advice would be helpful. Thanks.