I understand that 6PK1556 is the belt to use on 458. Continental should be making quality belts and I found this belt with a description of 6PK1555 - V-Ribbed Belt Trade Numbers 6 PK 1553, 6 PK 1554, 6 PK 1555, 6 PK 1556, 6 PK 1557 Does the last digit means that the length of the belt is 1mm difference from one another? Is it safe to use 6PK1555 instead?
