Doc..Im not familiar with the diamond airfoil..got the plans from ebay...the ribs had a notched leading edge,for, if I recall, a 3/8 or 1/2 square balsa piece..if that is what youre referring to...oh, the pushrod..in a hurry, wrong bending tools, etc. It will be rectified before flight, I promise. Dont tell "Billy G", but that Fox refuses to do anything but sputter off the prime. I recently installed Randys NVA and something aint right. It ran fine with the stock NVA. Been a bad month for engine problems, but like you say "have fun", and I am!