OK what is the difference other than length in these two filters. The 51522 fits on the 2002 chevy 5.3 and the 51042 is listed for the 2003 Chevy 5.3. Anyone know why GM made the change on this filter for it to be shorter for 2003 and up engines. The only difference I can see is the length. It isn't like it sits lower than the oil pan on the Silverado's 5.3 Just wanting to keep my stock simple with just one filter and not have to have two different ones on the garage shelf. Any reason I couldn't run the longer 51522?