Confuses, new spark plug wires don't match up
 

Comparing I believe what is the original model number of both ends of the spark plug cables to the new ones I'm not finding any similarity and the cables appear to be the same length.

Does it matter on the 2003 Chevy Tahoe LT 5.3 L Flex where those cables go?

ACDelco 9748GG Spark Plug Wire Kit

only if they are numbered for the corresponding cylinder, otherwise no, just replace them by matching the length....