Intake Manifold Bold length

[Carlton Huitt]

1973 C-10 350 engine, not original previous owners twice removed installed it.

I am trying to address leaking oil around the intake manifold bolts at the 3 and 4 position on each side of the manifold.

This was a botch job and it looks like they used whatever bolts they had in a coffee can rolling around the garage. One bold is 1 5/16 inch course threaded up to the last 1/4 inch . One bolt is 1 3/16 inch and threaded all the way up. No washers.

I ordered intake manifold bolts that were supposed to be for this model engine. 1 1/16 inch (MR Gasket #6080MRG). I wanted to get an opinion. Is it safe to use these bolts, the manifold appears to be approximately 1/2 inch thick?

Or should I seal up the bolts that were in there, add washers and pray?

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[C10MixMaster]

1/2 manifold 1/16 gasket leaves 1/2 of threads should be fine.. As a rule i like to catch at least as much thread as the width of the bolt , a little more if going into aluminum threads. Be careful there are a couple pushrods behind the intake bolt holes, if your bolts are too long they can hit.

 

[75gmck25]

I assume you already know you always need thread sealant and/or RTV for the 8 middle bolts that go through the head flange and into the lifter valley. If the threads are not coated with sealant the oil will wick up and pool around the bolt heads. IIRC the end bolts are not exposed to oil so you won't see oil there.

Bruce

 

[Carlton Huitt]

Thank you gentlemen for your helpful answers. I have the bolts should I install of the new bolts? If so would you suggest an approach to this so I can minimize risk of disrupting the intake to block seal?

thanks for taking time from your life to help a stranger!

 

[shiftpro]

I assume you already know you always need thread sealant and/or RTV for the 8 middle bolts that go through the head flange and into the lifter valley. If the threads are not coated with sealant the oil will wick up and pool around the bolt heads. IIRC the end bolts are not exposed to oil so you won't see oil there.

Bruce

Except RTV... do you mean that black goop? No not for bolts, use the white Permatex thread sealer in the tube.

 

[TubeTruck]

Try and clean the threads with a degreaser if you can. If they are oily it won't seal as well. Change the bolts out in this order if you don't want to take them all out, but the intake shouldn't move either way unless you pry on it. Change them one at a time and torque to 15, then once they are all swapped do your final torque.

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