For sale is a 1/2 aluminum Add-A-Rib. The rib measures 28" from end to end 3/8 in width and 1/2 in height. I had this on a 30" 391 and it fit absolutely perfect. Rib has front bead, did have midbead but that was removed. Has Add-A-Rib adhesive tape, so it's ready to install. I paid $145 shipped for the rib. Up for sale for $95 shipped USPS Priority Mail to your door.