I have this stock slant 6 tore down putting rods and mains in it and I might as well do the rings also. what would be the best rings to put in it. This is a stock slant 6 with about 65000 miles on it. Cast or moly. what brand. Do you have a part #. I have used Mahle before but this slant 6 is new to me. I want to stay stock. Thanks,Bill