On my 2003 Trailblazer LTZ with 4.2L , (Man. date jan 2013) I need help with which a/c delco part numbers are for all 4 pieces of the transmission cooler lines. Looking on ebay I think the 4 part numbers are ; 15817500, 15817514, 15817501, and 15817515. Am I correct in thinking if i purchase all 4 of those, then that's all I need in order to replace both complete cooler lines from the radiator to the transmission? One of mine sprung a small leak and they dont look very healthy.