ssolorado

does any body know the head torque on a 5.3 w/ alum heads. the only specs I can find are ls1 alum block or steel head & block

l_kusler

Depending on bolt configuration theres some slight differences but with all they recommend replacing the head bolts upon head reinstallation because they are torque turn specified and you stretch the bolts each time they are used. They must be torqued in sequence. Ensure your bolt holes are dry and clean or you will split the block. They recommend a little medium strength loctite on the threads of the 8mm bolts.

Step 1:
All 11mm bolts torque to 22ft/lbs

Step 2:
All 11mm bolts turn and additional 90 degrees

Step 3:
Depending on year and bolt!
If you have 2 different length 11mm bolts 3.94" and 6.1"
Tighten 1-8 in sequence an additional 90 degrees
Tighten 9 and 10 an additional 50 degrees.

If you have all same length 11mm bolts 3.94"
Tighten 1-10 in sequence an additional 70 degrees.

Step 4:
Tighten all 8mm bolts #11-15 to 22ft/lbs.

Heres the sequence:

Mangled03gmc

iTrader: (95)

That would be correct.... Good info

John

ssolorado

thanks, I spoke with a friend that works for the dealer and he gave me a torque spec of 115 flbs on the main head bolts and 22 flbs on the smaller bolts. thought I would share that with everybody. thanks for the input on the problem

OnyxSilveradoSS

iTrader: (4)

I thought they had to get streched, measured with an angle guage?

ssolorado

Well yes and no. according to him, the 115 flbs dry is really close to the 22+90+70. now adding up the rotation compared to the torque, it doesn't seem that far off. and a straight torque is alot easier to do in the truck. though I could be wrong and 115 flbs is alot of torque on a head bolt

l_kusler

Yea, but try turning all those degrees, you'd be surprised at how stiff they get! You know, i might have to try throwing a head on with the torque wrench to see how many degrees 115 gets me. I'm still pessimistic on a torque spec. Torque turn method was developed for more accurate clamping force. With conventional torquing you must take all factors into play, such as bolt head friction, thread friction etc, any bit of lube or lack of lube, depending on bolt torque instruction will also change this, whereas a specified revolultion of a particular thread pitch will result in far more consistent bolt stretch and relative clamping force. and it is no harder to torque turn a set of head bolts in the truck than out. Just mark the bolt heads, and measure out your degrees, make another mark. Use a long flex head ratchet or whatever (other than an impact lol) to turn to your marked point. Its not like you have to do the entire 90 degrees in one steady pull of the wrench.

kbracing96

iTrader: (26)

A 115?!?!?!?! You'll snap those things right off. I think my arp studs were only like 80 or 85. You really should just use the torque to yield process, or your looking for trouble.

l_kusler

my first post, just follow the steps, straight out of the book, i don't think there is any more questions that need to be answered, do it once, do it right and be done!

kbracing where your head bolt studs fine thread pitch on the tops?