XDR

In the process of installing my Mast Motorsports pan on my 5.3 that is in my Jeep. It is a '01 5.3 LM7. Mast says that a LS3 dipstick tube is required, I have removed my stock tube and when installing the LS3 tube it gets real tight where it necks down and I can only get about 1/8" of that portion in. The stock tube didn't appear to have an o-ring and the portion that goes into the block was alot shorter. Am I missing something? Attached is a photo of the 2 and you can see on the LS3 tube where its like an interference fit.

jduffett

Well, I'm guessing the original poster probably figured this out sometime in the last five years, but since I had the same question and couldn't find an answer anywhere, I figured I'd provide the answer. The lower portion of an LS3 dipstick tube is in fact the same as an LM7 dipstick tube, it's just that the one shown in the picture was broken off in the block. Looks basically the same as mine, and it broke off so cleanly that the tube looks like it is meant to be that way and it is hard to tell that the stub that's left in the block isn't just a machined feature. Once I dropped the pan it was pretty obvious. Even with the pan off and being able to pound on it from the bottom, it didn't come out easy!

G Atsma

Dipstick tubes aren't so much block related as they are pan related. LS blocks are all the same in that respect.