L33 head bolt torque specs

[Mr.Clark]

I'm looking for the correct torque specifications for the heads on the aluminum block L33. All I can find are generic specs for the 5.3, which are 22 ft-lbs initial pass, then 90 degrees on the second pass, then another 70 degrees on the third pass. This seems like WAY too much torque for an aluminum block.

 

 

I say this because I have had 2 stripped out block holes (#9, and #10), not the bolt itself and then a snapped #1 but I believe that is due to a weak bolt not over tightening as it snapped at 55-60 degrees on the last pass.

[CamGTP]

Did you copy/paste that question from this post 3 years ago from another forum lol.

 

https://www.silveradosierra.com/vortec-5-3l-v8/5-3-l33-aluminum-head-torque-t624826.html

 

Just busting your chops.

 

The LC9 which is an aluminum block as these torque specs.

 

37 ft/lbs first, then 59 ft/lbs then 60 degrees and final step is 60 degrees.

 

I thought that ended up around 70-75 ft lbs. Even torque is all that matters.

 

[Mr.Clark]

1 hour ago, CamGTP said:

Did you copy/paste that question from this post 3 years ago from another forum lol.

 

https://www.silveradosierra.com/vortec-5-3l-v8/5-3-l33-aluminum-head-torque-t624826.html

 

Just busting your chops.

 

The LC9 which is an aluminum block as these torque specs.

 

37 ft/lbs first, then 59 ft/lbs then 60 degrees and final step is 60 degrees.

 

I thought that ended up around 70-75 ft lbs. Even torque is all that matters.

 

Yes, I did as it was the only thing I could find relating to directly what I was seeking. I did not see the answer though, so sorry if I missed it. It was worded exactly what I needed.

[Brian715]

Also ensure you are using new bolts.  They should not be reused as they are torque to yeild (though some people do)

[Mr.Clark]

Yes, that I know, and have had to buy several sets as 9 and 10 stripped out after the 90 degree potion, which means new bolts.

[Mr.Clark]

21 hours ago, CamGTP said:

Did you copy/paste that question from this post 3 years ago from another forum lol.

 

https://www.silveradosierra.com/vortec-5-3l-v8/5-3-l33-aluminum-head-torque-t624826.html

 

Just busting your chops.

 

The LC9 which is an aluminum block as these torque specs.

 

37 ft/lbs first, then 59 ft/lbs then 60 degrees and final step is 60 degrees.

 

I thought that ended up around 70-75 ft lbs. Even torque is all that matters.

 

Where did you find this Data?

[CamGTP]

I had that on my computer from forever ago, so it could be wrong.

 

I went into Mitchel on Demand to double check just now.

 

The L33 specs are as typed above. 22 ft lbs, plus 90 plus 70 degrees. If you ask me, you'd be pretty safe just doing 22, 50 and 65-70 ft lbs and calling it good.