Hey Guys, did the fuel rail plug swap on my LMM this weekend.
Took about 20 minutes or so to get the Glow Plug controller, and mounts out of the way, that rear bolt was a pain, so i notched the mount to make it much easier, should I need to remove this in the future (see pic).
Everyone was right on GM using the hand of god to torque that damn bolt in the fuel rail, after some cursing, crying, and bloody knuckles she came out.
I used a 3/8" breaker bar (see pic) and a cut down 18mm socket so it fit much closer and better leverage. I did not use an extension, as I couldn't get it to fit and still keep the socket on the bolt. I just pulled with all my might a few times, and it finally just snapped lose, there was no give, it was tight, then it was loose, so just keep pulling on her!
I was able to get my torque wrench on there and get it properly snugged to 74lb-ft (it alerted me at 73.2 and I stopped).
It did take a bit to start, as I did not prime my fuel system via the fuel filter housing button, which would have alleviated the cycling without start issue, but after maybe 10 seconds of cranking the rig fired up.
No leaks and she's good to go.
Figured these pics may help those in search of what tools to use, and a first hand experience. 3 out of 5 wrenches for this install seems close from AlligatorPerformance.com, but only due to the difficulty of removing the bolt, not necessarily the overall job itself.
The pictures of the stock bolt are to show it can take quite the beating prior to being removed; I was getting pretty worried it was getting too rounded, so I was incredibly relieved when it broke free.
Don't be afraid to remove some bolts to move things out of the way. Disconnecting my charge tube from the turbo cleared up quite a bit of space to work.
Hope this helps a bit!