I bought what I was told was a running Chrysler 218 out of a '47 Plymouth Special Deluxe a year and a half ago. I got her down to the block, cleaned everything up, painted all pieces and parts, recently lapped the valves back in, and now I'm ready to begin reassembly. That's when I found out that my '47 Chrysler 218 is really a '57 Dodge 230 and it has been rebuilt before. For all intense and purposes the motors are the same so my gasket set will work, but the .030 oversize rings I purchased for the cast iron pistons of the 218 will not. What I really need to know is what size of oversized pistons I have. The pistons for the 230 are stock cam ground aluminum pistons (CDPD logo on them). 871354 O/S is cast on the inside of the pistons and 954809-x is stamped into the top of them. The piston diameter as measured with my dial calipers is 3.259in. Any and all information will help - thanks.