Cupped washers

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70Duster340

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I'm searching for those washers to attach the hi-po exhaust manifolds. So far, what I have found are sorta pricey, but that's not the problem currently. How many are required? I've gotten differing information, depending on where they are available. I've seen that 4 are needed, 1 on each corner. I've also seen that as many as 12 are called for.
Can anyone give me a solid number? Also, is there a good source for these. I have all the studs and sleeve bolts, just missing the cup washers.
Thanks!
 
From the factory, AFAIK, for 318 cars; there were only two per side, one on each end, under the fine-thread studs.
but 340 cars, there mightabin more. If they fit, I would install as many as possible.
They were NOT there to solve a sealing issue. Rather to allow the manifold to walk back and forth on the thin shim gasket, and to help prevent the snapping of the fine-thread studs.
I put one on every bolt/stud; six per side.

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If you had thick gaskets and header bolts, you wouldn't need them. But you may still need a mechanical way of keeping the bolts from backing off. Which is why I have super-thick gaskets, ARP fasteners, and those cup-washers under every bolt .. and my TTI/fat-flanged headers never come loose.

IDK anything about sleeve-bolts.
 
70Duster340 said:
I'm searching for those washers to attach the hi-po exhaust manifolds. So far, what I have found are sorta pricey, but that's not the problem currently. How many are required? I've gotten differing information, depending on where they are available. I've seen that 4 are needed, 1 on each corner. I've also seen that as many as 12 are called for.
Can anyone give me a solid number? Also, is there a good source for these. I have all the studs and sleeve bolts, just missing the cup washers.
Thanks!
Click to expand...
Look a photos in the shop manual. My recollection is 4
 
70Duster340 said:
I'm searching for those washers to attach the hi-po exhaust manifolds. So far, what I have found are sorta pricey, but that's not the problem currently. How many are required? I've gotten differing information, depending on where they are available. I've seen that 4 are needed, 1 on each corner. I've also seen that as many as 12 are called for.
Can anyone give me a solid number? Also, is there a good source for these. I have all the studs and sleeve bolts, just missing the cup washers.
Thanks!
Click to expand...
Well, you KNOW it can't be twelve, as there is no way the cup washers will fit under the sleeve nuts on the second and fifth bolts with 340 manifolds.
Some of the confusion may come from the fact that the 273/318 manifolds used washers under the four outboard bolts/studs, but those manifolds didn't use sleeve nuts. The 340 manifolds used sleeve nuts on two and five, and washers on the ends. I have never seen washers on the two center bolts from the factory, but if you do elect to use them there make sure you use slightly longer bolts in order to get full thread engagement.
 
Mancini Racing is where I saw that. They want $3.99 each for the washers. Thought that was a bit high, but supply and demand creates the market.
I found some that were for a Jeep CJ that looked identical, but were much cheaper. Don't know if those would work in place of the OEM ones. I tried crossing the part numbers, but that didn't work. I don't need the entire kit of nuts, sleeve nuts and washers, but locating the washers isn't easy.
 
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