Intake torque specs/Vortec Big Block

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8T7K5

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So I'm about to be putting in new injectors in my 99 K2500 Suburban. I've been looking at Alldata for my truck and it's showing two different torque specs for the upper intake. According to a TSB issued on 5/96, it says this:
"A revised torque sequence, torque values and use of a threadlocker on the upper intake manifold bolts has been issued to correct this problem.

Use the procedure from the appropriate service manual on vehicle repair section to replace the gaskets between the upper and lower intake manifold, EXCEPT APPLY THREADLOCKER and use the torque sequence in place of the torque shown in the service manual.

THE TORQUE VALUES AND SEQUENCE IN THE SERVICE MANUAL HAVE BEEN REVISED AND THE USE OF A THREADLOCKER HAS BEEN ADDED. USE THE TORQUE VALUES AND SEQUENCE IN THIS BULLETIN."

It goes on to say torque all bolts in sequence on the first pass to 12ft lbs then on the next pass torque to 18 ft lbs.

Under the same section on the intake, the installation procedure calls for 72 inch lbs on the first pass then 10ft lbs on the second pass. Which one is correct? I don't want to have to do this a second time.
 

mtl111

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Took a pic out of my 1999 GM C/K Service Manual set. The TSB you have is from 1996, correct? If so, I would use the info in the pic as it was printed 3 years after that TSB was issued. I hope this helps you out!
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mtl111

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No problem man! [emoji106]

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454cid

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I wouldn't have thought the upper intake bolts would be that big a deal. It's not like it's being bolted to three different pieces of a dissimilar metal like the lower intake.
 
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