My Haynes Manual says the torque spec. for 89 and later Head bolts are 68 ft lbs. Can anyone confirm this.. I do not trustthis manual.

 

Doesn't matter what year, as long as it's between 55 and 2000; or, whether it's a 262.5, 265, 267, 283, 302, 305, 307, 327, 350, or 400.

60-65 is good. Anything over 65 is too much and runs the risk of blowing between the 2 center cyls. Go over-tighten your valve cover bolts, and observe what the valve covers do; how they bend UPWARDS in between the bolts. Heads do the same thing.

I prefer to do them in 3 stages, like, 35 - 45 - 60. DO NOT use a "clicker" type wrench. Use a beam or dial type. Use Loctite "hi-temp automotive thread sealer with Teflon" on the threads and under the bolt heads. GO back over them a couple of times inthe torquing order and set them to where the wrench reads just over 60 WHILE THE BOLTS ARE MOVING (this being the problem with a "clicker"), NOT while they're stopped. They might take 65 or 70 to break loose, then 55 to keep moving: keep tightening until they reach 60 WHILE THEY ARE MOVING.

 

Spec for a 305 is 68 lbs in three passes.


25 lbs.
50 lbs.
68 lbs.

GM 1052080 is recommended for the head bolts, but new bolts usually come with the threads pre-coated.

Make sure all fluids are out of the bolt holes because that will effect the torque spec. and even crack the block when torquing. Clean the threads in the block with a thread chaser, as a tap will take away the slight taper the bolt hole has.

 

That's what my manual says as well but not recommended do it in 3 passes like the other guy said not sure on why not to use a clicker type torque wrench but I've used it before on my other project nothing bad happened but if it's paranoia just lower it a smidge like first pass 23 then 43 then 60 I can't say much on the whole dial type I'm the type to not over do it as to me that's to much can lead to future bolt breaking when removing