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2004 lm7 head torque

Jon91

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Jon91 New Member

Jon91

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Im replacing my 706 castech heads for some non-castech 862 heads. I read couple of torque sequences for the lm7 and they have two types of torque to yield options. I have a 2004 5.3 LM7. What sequence would I use for the 862?

 lm7
 
 
 
 
 

 

This one is for 2003-2004 years

  1. Tighten the M11 bolts to 22 ft. lbs. (30 Nm).
  2. Tighten the M11 an additional 90 degrees.
  3. Tighten M11 bolts 1-8, an additional 90 degrees and M11 bolts 9 and 10 an additional 50 degrees.
  4. Tighten the M8 bolts (11-15) to 22 ft. lbs. (30 Nm). Tighten all the bolts beginning with the center bolt and working outward, alternating sides 

 

 

Another says:

This one is for the 2005 year.

 
 
 
  1. Tighten the M11 bolts to 22 ft. lbs. (30 Nm).
  2. Tighten the M11 an additional 90 degrees.
  3. Tighten M11 bolts, an additional 70 degrees.
  4. Tighten the M8 bolts to 22 ft. lbs. (30 Nm). Tighten all the bolts beginning with the center bolt and working outward, alternating sides

 

 

Why would they make two different torque options for the same engine?

0996b43f80207daa.jpg

04z71crew Enthusiast

04z71crew

Posted
Posted

I just completed this repair on my 2004 5.3 LM7. Have you pulled your heads already? How many bolt sizes do you have? They changed bolt styles in 2004 so it depends on when your truck was produced. If you have only 2 bolt sizes follow the second diagram. If you have 3 bolt sizes with #'s 9-10 being smaller than 1-8 you should follow sequence #1. My truck was produced in 2004 and I only had two bolt sizes. If you haven't already pick up the 862 heads I would highly recommend a set of 799's or 243's. I installed a set a 799's with a full valve job and milled them .030. My castech 706 heads failed. 

Jon91 New Member

Jon91

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Oh ok. No I haven't taken out my heads yet. I got thick sludge after having it sit for a month without being started. I guess the crack got through the oil. Changed the oil couple time and everything went back to normal. I already got a pair of 862 noncastech heads for 80 bucks. I already "ported" them (hack job lol) but they look good. Followed a lot of youtube vids and forums. Also got some 2inch intake valves. Im also going to throw a 216/220 .600 cam in it since it'll be taking off the heads. Might as well do everything I was planning to do to the truck at once. Im just waiting to get everything I need to do everything in a week.

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