[COBRAGAR]

yes there is a standard rotation pump w/4 bolts in the pulley. like you have in the picture i believe it to be a pump a of 1987 mercury w/302 or 351 .look in the march pulley infomation if not call march pulley they have the info.if i call i will try to supply info later to day. no need to change the timing chain cover. i believe # fms-m-8501-e351s or fms-8501-g351 from summit to be what you are looking for. look close a the pulley on this pumps and you will see about 8 hole for diffrent application . hope this helps