That's what I was thinking as well cj847 when I needed to replace my tube. Seems like the stock one should work, however, I went ahead and replaced mine with the part numbers suggested by Holley. I have this same knockoff pan on a 2004 5.3 and I went with the GM parts. They ended up being sub-par quality. The dipstick end didn't even fit through the end of the tube and I had to ream it out! I'm curious to hear how the Dorman parts fit.
