440 Six Pack Intake Manifold Bolt Tightening Sequence

[MoparHonda]

Does anyone know the tightening sequence for the intake manifold bolts on a 440 six pack? The '70 service manual only says 40 foot pounds, does not show the sequence to tighten the bolts.

('70 Plymouth GTX, 440 six pack.)

 

[Cranky]

I always start in the middle and work my way out with a criss cross pattern and only tighten evenly and a little at a time.

 

[Lionized]

Indeed. Inside out/cross pattern. Careful with aluminum intakes using bolts with no washers.

 

[747mopar]

Like Cranky says^^^

It's the same principle with any head or intake, start in the center and work your way back and forth as you move outward. I usually go in 3 steps before reaching the torque spec.

 

[Cranky]

Indeed. Inside out/cross pattern. Careful with aluminum intakes using bolts with no washers.

It's a good idea to use washers on aluminum....

 

[Lionized]

It's a good idea to use washers on aluminum....

Absolutely.
Some dudes don't know though and find out the hard way that it's not a great idea.

 

[Ironbuilt]

With aluminum, always use "baby steps"., Like Cranky said, start from the center and work your way out. But always use "baby steps". For example, start at 30 lbs. Tighten all of the bolts from the center out. Then increase to 40 Lbs.

 

[HEMI-ITIS]

I always start in the middle and work my way out with a criss cross pattern and only tighten evenly and a little at a time.

Take it down in 3 or 4 steps.

 

[Daves69]

FWIW...……

......service manual only says 40 foot pounds...…..

IMO, You surely don't want to over torque them as the thread engagement in the heads are minimal to begin with.

 

[ksurfer2]

I just reinstalled my 6bbl manifold, and worked from the inside out, criss-crossing as suggested. This was two weeks ago. Last weekend, I went back and re-checked the torque. It was surprising how much the bolts needed to be re-torqued after a few heat cycles.

 

[MoparHonda]

Thank you very much, I'll also re-torque them after a few engine runs.