Magnum exhaust manifold studs.

[Bronze Barracuda]

Where can I find some magnum exhaust manifold studs. I've been searching all over the place, and I cannot find any studs long enough. I ordered some from Amazon that said they are 2.5 inches long. I figured that'd be long enough as the exhaust part where the manifold studs go is 2" long. I figured 1/4 inch in the head and 1/4" to bolt on the other end. But when they arrived they were only 2/14" long. I could get some la ones and put the studs in the two inner locations I suppose.

 

[RAT ROD AL]

Try BOLT DEPOT

 

[Bronze Barracuda]

Try BOLT DEPOT

Worth a shot, all they have is fully threaded 5/16 stainless. I could just buy some 5/16 stainless threaded rod from Lowe's or home Depot. Does anyone know if the bolts holding the manifolds have to be a finer thread on the rods?
I'm guessing no, because the rest of the bolts will all be 5/16 x 18.

 

[RAT ROD AL]

Ya, I looked also. not much for studs there. sorry !

 

[Bronze Barracuda]

Ya, I looked also. not much for studs there. sorry !

Yep it's kinda nutty. There must be millions of magnum heads out there. What the heck are people using?
I did some google machine research, found out that stainless can be used for exhaust manifold studs. Although you must use stainless nuts and washers
There will be galling, at least that's what the Google gods said. So I guess galling isn't detrimental maybe unsightly?

 

[RAT ROD AL]

What about Fastenal ?

 

[Professor Fate]

Are you trying to use the Magnum manifolds on a Magnum or an LA? If it's on a Magnum there's no need for studs, all the exhaust bolt holes are dry. They just used bolts from the factory. If you're putting them on an LA, just use bolts and sealer on the outer two bolt holes, it'll seal just fine. The studs were just used to maintain the seal on the outer two wet holes in case you need to remove the manifolds- with bolts, you just have to remember to drain down the coolant a bit before you remove the manifolds.

 

[PROSTOCKTOM]

Stay away from hardware store stainless steel all thread and stainless bolts from a hardware stores. Most of those are Grade 2 at best. If you want stainless studs call ARP.

ARP only has about 10% of what they manufacture in the catalog, so if you don't see what you're after that doesn't mean they don't have it.

Also McMaster Carr is a very handy place to get most anything it takes to run a factory, so they too have lots of options. McMaster-Carr

Tom

 

[Bronze Barracuda]

Are you trying to use the Magnum manifolds on a Magnum or an LA? If it's on a Magnum there's no need for studs, all the exhaust bolt holes are dry. They just used bolts from the factory. If you're putting them on an LA, just use bolts and sealer on the outer two bolt holes, it'll seal just fine. The studs were just used to maintain the seal on the outer two wet holes in case you need to remove the manifolds- with bolts, you just have to remember to drain down the coolant a bit before you remove the manifolds.

Yes magnum manifolds on LA heads. I forgot about the water jacket intrusion. I was thinking is also easier to set the gaskets on the studs when mounting. But then again I've recently heard that early engines particularly 273 never used exhaust gaskets. Thanks I may just mount them with bolts like you mentioned with some thread sealant on the outer holes.

 

[Bronze Barracuda]

Stay away from hardware store stainless steel all thread and stainless bolts from a hardware stores. Most of those are Grade 2 at best. If you want stainless studs call ARP.

ARP only has about 10% of what they manufacture in the catalog, so if you don't see what you're after that doesn't mean they don't have it.

Also McMaster Carr is a very handy place to get most anything it takes to run a factory, so they too have lots of options. McMaster-Carr

Tom

Cool. Thanks I never heard of McMaster Carr

 

[Professor Fate]

Yes magnum manifolds on LA heads. I forgot about the water jacket intrusion. I was thinking is also easier to set the gaskets on the studs when mounting. But then again I've recently heard that early engines particularly 273 never used exhaust gaskets. Thanks I may just mount them with bolts like you mentioned with some thread sealant on the outer holes.

Keep in mind, if you start using studs that long, you will NEVER be able to remove the exhaust manifolds once the engine is installed; there's just not enough room in an A body engine bay.
And no, exhaust gaskets weren't used on LA exhaust manifolds, other than the tin heat shields/plug wire shields on some motors. For that matter, Magnums didn't use them either.
If the mating surfaces are less than ideal, you can use them (gaskets) to seal things up. Otherwise I'd just true up the surfaces of the manifolds (a bed sander works good enough for that job), bolt 'em on and go. Throw some hi temp copper gasket seal on there first if it makes you feel better.