Thanks for the response. The numbers you list are part numbers for replacement parts which are called out in the MPC. All 3 combinations are listed, A,C & M. It makes sence that C/M are an either /or because both are 4 leaf-665 lb load rated. The A suffix part number is 650 lb rated. Since I can see the stripe I will lightly sand it to see if it really is silver. It looks like these are the 665 lb rated springs because of the AA. The 650 springs would have been marked 5556-J, AB.