intake and header not lining up

[dalefan88]

i got a offenhauser intake and a hedman single outlet header. i painted the header today and when it dried i put the intake and header together to see how they looked. i noticed that the flang on the header is not as thick as the manifold. so how the heck are you suppose to bolt these together on the head. any ideas.

 

[Cheepjeep85]

Just an idea but you could grind a notch in the washer that is on the bolt, they're pretty thick it might work. Or tack on a thin piece of metal onto the header where the washer rests.

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[dalefan88]

Just an idea but you could grind a notch in the washer that is on the bolt, they're pretty thick it might work. Or tack on a thin piece of metal onto the header where the washer rests.

Sent from my DROID2

i thought about adding metal but i cant weld

 

[Rescue Diver]

For my mix and match head swap using an 80-85 intake with a 95 manifold, I cut some thick metal pieces to bridge the gap between the intake and exhaust flanges, because they're spaced further apart than stock and the round cupped washers won't reach the tabs on the 80's intake when bolted to a 95 4.0 head.

The easiest thing I can think of would be for you to just cut some rectangular shims from metal that's the thickness of the difference between the intake and exhaust flanges and just hold them in place while you tighten down the bolts and cub washers? They shouldn't move once it's torques down.

 

[IOPort51]

not being able to weld I think I would try a piece of tubing about twice as long as the difference and notch one side to make up the difference. This way the pipe would stay on the bolt under the washer. I know it would smell something awful but I think I would use a small amount of RTV to hold the pipe and the washer together.
If you have a Mapp torch you may be able to do a braze.
everything you need is at the home despot.

 

[MN CJ7]

i got a offenhauser intake and a hedman single outlet header. i painted the header today and when it dried i put the intake and header together to see how they looked. i noticed that the flang on the header is not as thick as the manifold. so how the heck are you suppose to bolt these together on the head. any ideas.

Headers typical have 1/2" flanges for mounting. The water jacket intakes 1981? and newer have 1/2" flages and will work with std hdw. The cast iron manifolds and the more modern alumium intake manifold use different length fasteners. So if you U Pull a alumium intake take the bolts & Mtd Washers. The old cast iron manifolds had a approx 1 inch mtd.

.... i recommed the alumium intake for use with headers.

The cast iron manifolds has a thick flange with Stand Offs so not easy to mate these with headers. I have seen approx 1" shims so the mtd flanges are the same height. This is a tricky solution. I have also seen guys grind off the taller flanges so they are 1/2" tall and match the header.

The AMC 258 i6 / 4.2l has a very long manifolds and are prone to loosening up. They need to be snuged up in a process order... start in center and go out in a circle, then repeat till you are at torque rating. HOT & RUSTY so use antizeise on manifold bolts.

NET NET... the alumium intake will take weight off, its a better intake than the cast iron. The alumium jacket and electric heater is a much better way to heat the intake to 195F operation temp vs cast iron. the first aluminum castings of 1981? are rough and the casting is not the quality of the alumium intake castings of the 84 range or so. Per a Mech Friend that we talked about this... The rough older aluminum intake will hold fuel, be better for slow moves. But rough slows down air flow and the motor is a pump. The newer approx 84 intake is smoother and the air flow is smoother. I had both in my hands and there is quite a difference. I have a 81 rough manifold

 

[dalefan88]

good replies guys i want to keep my offenhauser intake so i think im going to find some metal tubing and cut out spacers and see if that will work. it sounds like the newer stock intakes would work good but i already have the offy.

 

[MN CJ7]

maybe post a few pics so we can see?

The Offys are pretty common, but I thougth they matched on the flange dimentions.