Screw for the exhaust manifold

[freds]

Trying to install the drivers side exhaust manifold on my 350 engine. Every thing has been going good except the back bolt, for cylinder number one has a. Curves on not allowing the screw to go in. Yet, I know a screw was in that hole. Maybe, a different type of screw head. ?

[Pro299]

Have you tried installing all the bolts loosely and then tightening once they're all started? Manifolds are not precision pieces. Sometimes a hole is off just enough that one will not line up perfectly, but will work fine if the manifold has just a bit of wiggle room.

[LockDoc]

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Another problem can be that the holes in the manifold can have a bit of rust buildup inside. I usually run a drill through them to clean any rust out of the hole before trying to bolt them up. That gives a little more wiggle room. The bolts are basically all the same with a 9/16 hex head.

LockDoc

[freds]

I believe i probably did not explain correctly, the problem is the curvature of the exhaust pipe for the number one cylinder. the 9/16 hex head flats are leaning against the pipe.

[ChevyRacefan]

Originally Posted by freds

I believe i probably did not explain correctly, the problem is the curvature of the exhaust pipe for the number one cylinder. the 9/16 hex head flats are leaning against the pipe.

So these are headers not iron manifolds,
back all bolts out, and screw them all in slowly together. say 2 turns each (all the bolts), then 2 more turns each, down the line. till they are snug up against the head.
If it is the bolt head is to big to turn when flush with the header flange, you need to get smaller head bolts. IIRC my ARP bolts are 3/8 wrench heads

[RustyPile]

Originally Posted by freds

I believe i probably did not explain correctly, the problem is the curvature of the exhaust pipe for the number one cylinder. the 9/16 hex head flats are leaning against the pipe.

You have the wrong bolts.. These are the bolts you need.. https://shop.advanceautoparts.com/p/...aust%20Systems

[sick472]

You may have to use a Socket Head Cap screw. They have a smaller head and use an allen wrench instead of a box wrench. I'm not real clear on the exact location of you problem, but I have had to used the SHCS's on occasion for head/wrench clearance on headers before. If you need to use a washer also, metric washers will have a smaller outer diameter that will work well with the SHCS.

[Grumpy old man]

Are you using header bolts ?

https://shop.advanceautoparts.com/p/...0&gclsrc=aw.ds