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73-87 Chevy _ GMC Trucks => Performance => Topic started by: Bitzer! on January 15, 2012, 08:58:49 am
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Hi guys, HELP!
Started to fit the headers and have concerns. The manifold does not sit flush against the block.
I'm wondering if I have the wrong headers, the block is square holes & the exhaust is round. Square peg? or does the round hole sit against the gasket then against the block and leave the gap between the outlets?
hope this makes sense!
cheers in advance!
Andy
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Generally speaking, your headers are suppose to match your heads. Round and round, square and square.
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what type of headers do u have, are u trying to fit them with out the gaskets?
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The headers are Summit 4 branch. I have the right gasket but concerned about the gaps between each port. The manifold doesn't fit flush against the block at any point.
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The headers are Summit 4 branch. I have the right gasket but concerned about the gaps between each port. The manifold doesn't fit flush against the block at any point.
Hey Bitzer, I am confused. Is the gap you are talking about between the header and head, or between the inside head and the manifold, or manifold and block ?
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Is it the gap between the header flange and the head? Does it do it on both side of the engine? I had run some Summit headers a while back on my 350 and it seems that the header flange would fit flush against the head without a gasket installed. They would just lay right in there nicely. Check and make sure something isn't in way. Frame, starter ect...
If I remember correctly my headers were round tube and my heads has square exhaust holes.
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ogh. i think i saw the same thing when it was installing long tube headers on my 80 c10 sbc350. the outer 2 pipes on the header flange to head were not flush, they had to be drawn in when tightening the bolts down. i think that u will be ok with the ones u have as long as the pipes and holes all match up. idk. :-\
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warped flanges? Take a known straight edge and check the heads and header flanges...
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Sorry guys I'll try and be a bit clearer. The exh will bolt up tight and cover the holes. Between 3 +5 there is a gap you can see thru even tho it's all tight?
I'll try and post pics tonight if needed!
Cheers
Ps - sorry - yes I'm fitting them to the head NOT the block hahaha a senior typo crept in!
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So let me ask this question. Before you mounted, did you take a straight edge and check the head surface and the header surface to make sure both were flat and flush ?
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Bake74 - no, straight out the box. There are 4x round welds that sit proud by 4-5mm, these fit against the head. When tight, all four outlets are fully covered and look to be fine.
My concern is the plate the rounds are welded to sits proud by the 4-5mm.
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Pic is best.
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Right, here we go! After another look tonight I think I may get away with bolting it up but if anyone could take a quick look at the pics and confirm for me.
Worse case scenario I grind out the round rings and using the gasket as a template weld squares!
Quite confident I can do that if that's the better way.
Cheers
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Youre good to go. That gap is ok. the surface area contacting the gasket is the only thing that needs to be true. The only thing I would be concerned with is over tightening the bolts.
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Woop Woop!! Cheers Beastie ;)
Any chance there is a torque setting for the bolts??
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I dont remember the torque value. Check with who made them. Also, you will have to re-tighten the bolts after a few heat cycles because everything settles.
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I would get them about 20-25ft/lbs and then after you drive it, retighten them.
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Thanks for the good advice guys! - oooh I love this site!!