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I am rebuilding my 282 and am wondering about the exhaust manifold being set back approximately 1/16 of an inch from the intake. is this normal? If so what takes up the space?Currently there are round spacers there but they leak. Any help would be appreciated.

The intake and exhaust portions are two separate castings joined by screws at the box section under the carb to form the single manifold assembly. I don't believe it is keyed in position or has a gasket but rather just two smooth milled surfaces touch together. If all the intake runners are out of position it is possible something has jarred the manifold-- maybe it was dropped -- causing the pieces to slip at the junction. Possibly it could have been assembled incorrectly and tightened down without the use of a straight edge or being on an engine block to ensure the levels were all the same. If only one or two of the ports are out of position then it has probably warped and needs to go to a machine shop.

Usually after use the screws joining the castings become thoroughly rusted to the threaded holes or otherwise very well adhered and it may be extremely difficult to loosen or remove them without breakage. If that is the case, unless someone has been there before and has a better idea, probably the only option would be for a machine shop to see if they can disassemble or else mill all the ports to the same level. If the amount needed to get it level is a fair amount then I would be concerned that removing a lot of material could weaken or ruin the manifold.

Here is an illustration of a different manifold showing the 2 piece construction which is typical of how they were all made.

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As Howard indicated, the two surfaces must be on the exact same plane and without spacers. If not a simple alignment issue, then possibly someone mismatched the intake and exhaust manifolds from two different years and models, then tried to compensate with the spacers but they definitely shouldn’t be there!

Thanks for the advice guys. I am currently making extra gaskets for the exhaust ports. Iknow this isnt right but I dont want to split the manifold and possily break it. The body work is also taking a lot longer so I might not drive it till May.

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If the 3 bolts are loosened you might have enough wiggle room to correct the space across the intake /exhaust flanges. I took mine apart years ago without breaking bolts. Also there is a “hot spot” gasket between the manifolds that came with my rebuild gasket set. I guess it’s also possible somebody milled the exhaust manifold and not the intake. As Howard noted there is not much meat on the manifolds to mill, so if needed be careful.

Hey BSer, I would sure investigate JT120's suggestion, as when I put my manifolds together, they were way out of alignment. However with the suggested straight edge and some adjusting, I got a perfect 'plane' of alignment and they bolted on to the engine with no leaks. They can be moved around more than you might think before the manifold to manifold nuts are tightened up. Worth checking anyway, might be an easy fix! Chris.

Sounds like a job for half a bucket of penetrating oil and a propane torch.

Yes, and when installing on the motor, leave the fasteners loose at the joint of the two castings, bring the flanges up to torque to the block or head, then tighten the joint cap screws. Gives you the best shot at a good air tight seal. Any opening at the head or block will simply blow out the gasket and sound like you have no muffler on the exhaust or cause such a vacuum leak on the intake that it will not idle right. I use a spray bottle of water on start-up, the exhaust will bubble at a leak and the intake and carb areas will dry instantly as air is sucked in showing the leak.

Brass nuts to fasten the manifolds to the engine block.

If you are removing / replacing manifold studs be sure and use a good thread sealant into block. I believe it’s the first stud in line that goes into the water jacket and might require attention.