What are people using for manifold bolts? Pro Fab

04LB7yz

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Aug 16, 2013
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Just wondering what guys are using for Manifold bolts for Pro Fabs. I have all of the factory bolts that are still in good shape. Should I just use those? Thanks for the input guys!
 

RickDLance

Active member
Feb 14, 2007
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The manifold bolts are 10 - 1.5 x 30 allens. The stock up pipe bolts will work.

Normally no washers. We have had a couple of people say theirs backed out and they are using lock washers on theirs.

We recommend tightening them and then drive it around making sure it is gets up to temp. Then re-tighten.
 

Animals1234

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Jun 8, 2017
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Rick,

Sorry for bringing up an old post but I had a question on torque spec. I'm putting together my motor together and have come across two different torque specs for the manifold. Some people are saying 28 ft lbs and others are saying 42. Which one would be correct? I did 42 ft lbs and plan on checking after driving it around.

Thank you
 

ikeG

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Apr 19, 2011
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The profab instructions say 29 & 39 if I remember correctly. Its definitely less than factory specs. Just did a set 2 weeks ago but I sent the instructions with the customer

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rcr1978

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Apr 1, 2007
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If you have the stainless bolts do yourself a favor and throw them in the garbage they are the equivilant to grade 3 bolts almost. They were nothing but headaches for me, 2 sets of up pipe gaskets and one set of manifold gaskets later I got new bolts and finally trouble free. Every 200 miles I was getting a tick, I would get in there and find half the bolts loose. I was like wtf :mad:, well retorqued them and same shit another 200miles, after blowing the gaskets out the last time I finally figured old the bolts were garabage. Those who have nice itchy blankets on everything know how big of a pain in the ass to change gaskets or retighten the bolts.
 
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sawmilldmax

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Apr 2, 2013
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I had some bolts Teflon coated because I didn't want to look at rusty bolts, but I guess that was a mistake because they kept loosening up. I finally got them to stay tight though.
 

ikeG

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Just removed a set that have been installed for roughly 10 years, they are THE brand A2-70 stainless socket head cap bolts. M10 x 1.50, 35mm long. No washers.
74ea538613c10abf92a9c948155cba29.jpg


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ikeG

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Apr 19, 2011
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Sorry for the delayed reply ikeG.

If possible I need all the lengths of the stock bolts as I am returning my manifold to stock and have thrown out the old hardware from when I upgraded my manifolds.
All bolts are M10x1.5. There are 13 that are 61mm long. There is one on drivers side that is 36mm long. Then the 2 long ones, 101mm, 1 per side. Then the 4 studs. They are M10x1.5 at the cylibder head and M10x1.25 at the nut. 75mm long.

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