Part Number AEC652541 (PMA Nut 1 2 20Unf Cylinder Base in stock with ready to ship. Get an instant quote for Engine Components part number AEC652541 (PMA by filling form below with your desired order quantity, targeted price and the expected order-fulfilment date. Get instant quote for AEC652541 (PMA. Our dedicated account manager will get back to you within 15 minutes.