David, looking good. Try to move those batts more up front. Also the ecu and rx, and is possible the jetronic valve. Moving the engine more forward will help you eliminate some extra lead in the nose. You said the pipe is too short. But in the pics looks like it need to be more to the rear. You shold left a gap abot 3/4 inch from tip of exhaust cone to lip of bell mouth in the pipe. Just my opinion from what I can see in the pics.

Saludos,
Alex