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Hello to all. When I bought my M37 it came with some parts one of which was what appeared to be a NOS Intake manifold still wrapped up in the box.When I opened it to inspect it I found that all the drilled holes were not threaded (see arrows in pic's )is this normally how NOS intake manifolds come?

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Mine too were threaded on my NOS intake.

That could also be a blem that was never finished. I'd give it a real good inspection before doing any tapping on it.
When you do tap it, go slow and easy. Backing the tap out frequently. Cast can crack really easy.

I've seen many NOS components over the years that had all sorts of similiar issues. Many times, issues such as you have discovered is why new parts were sold as surplus. We discovered a batch of transmission shafts some time back, the vendor advertised as new NOS surplus. We discovered that every one in the particular lot was simply spider webbed with cracks, likely a goof up in the heat treating process, nothing but scrap metal sold as first class parts. Did the vendor know before, probably not. Did they pull the remainder of the lot when we discovered this, probably not. This is another reason I'm not a great fan of some NOS parts. Vendors should check their surplus stock very close before passing it on for sale, but obviously many either don't check, or chose to rip a buyer off knowing there are issues and not telling, it happens. Many don't check before they buy, cause their intention is to pass it on regardless if they can sell it. There are honest and straight up vendors, there are also bad apples, check before you buy if you are unfamiliar with sellers, this forum is a smart place to ask questions of reference before you buy.

It may be that the threads are the only issue with your manifold, if so, that can be easily corrected, but fair warning, check it completely with a fine tooth comb. It may very well be that a dimensional flaw of some sort exist was the real issue, thus the remaining steps in the manufacturing process were eliminated. Would a supplier pass on junk to the US Government? In a heart beat, they just pay an exorbitant price for it, find out later it was junk, then pass it on to some other sucker, and so it goes.

You brought up some good points Charles, I don't think its worth it. I guess I'll just use it for a door chock. Thanks guys

Charles, You nailed this one perfectly.

I've seen parts like this in the past while doing auto rebuilds. I would magna flux that manifold prior to putting any tapping time into it. Have the port side checked for flatness while your at it.

If it all checks out you shouldn't have any problems tapping the holes. Double check that the holes are drilled to the proper size so that you don't break a tap off.