Open bolt hole in 426 hemi head - exhaust side

[doberjoe]

Installing the factory cast iron exhaust manifolds on my 426 hemi crate motor. On one end there are two bolt holes that appear to go into the head where a head-bolt goes thru the head. The hole is "open" to the atmosphere. Should I plug it with a stud? The manifold bolt goes into one of the two holes, but the other hole is unused (and unfilled).

Do I leave it open, or do I put in a flush stud with some sealant on it?

Thanks!

 

[gtx6970]

Leave it open.

I don't think any are wet on a hemi

 

[Bird 426]

Picture of what you are talking about?

 

[Runcharger]

No attention needed.

 

[not so famous bob]

Installing the factory cast iron exhaust manifolds on my 426 hemi crate motor. On one end there are two bolt holes that appear to go into the head where a head-bolt goes thru the head. The hole is "open" to the atmosphere. Should I plug it with a stud? The manifold bolt goes into one of the two holes, but the other hole is unused (and unfilled).

Do I leave it open, or do I put in a flush stud with some sealant on it?

Thanks!

are you sure your not looking at the oil return hole in the corner of the head ? wedge motor don't have them ...hemis do...

 

[doberjoe]

Picture of what you are talking about?

thought I had a picture on my phone, will post one as soon as I can get back to the shop

 

[doberjoe]

thought I had a picture on my phone, will post one as soon as I can get back to the shop

here are some pictures. Passenger side (rear) shows an open threaded hole. Driver side (Front) shows a half-hole visible.

 

[not so famous bob]

here are some pictures. Passenger side (rear) shows an open threaded hole. Driver side (Front) shows a half-hole visible.

View attachment 1822849

View attachment 1822850

scusem Waugh , I thot you were talking about inside the head .
I wouldn't worry about that f it doesn't go thru to the water jacket , or such...
assuming you have the right manifolds on it , been too long since I had my hemis ?????/

 

[doberjoe]

scusem Waugh , I thot you were talking about inside the head .
I wouldn't worry about that f it doesn't go thru to the water jacket , or such...
assuming you have the right manifolds on it , been too long since I had my hemis ?????/

these are original factory exhaust manifolds. The hole appears to go into a void through which a head bolt passes.

 

[not so famous bob]

these are original factory exhaust manifolds. The hole appears to go into a void through which a head bolt passes.

wondering which heads you have , maybe a factory head that was configured for headers ----??????
I`d put a sealer an it and use a bolt that wont quite touch the head bolt and fugetaboutit .

 

[not so famous bob]

here are some pictures. Passenger side (rear) shows an open threaded hole. Driver side (Front) shows a half-hole visible.

View attachment 1822849

View attachment 1822850

boy something don't look right , Dont remember either of mine having a bolt hole under the manifold !
You sure you have parts matched right ? We are talking about a 426 hemi aren't we ? Manifolds look wrong / best I can remember , show a pi of the whole manifold >>..

 

[doberjoe]

boy something don't look right , Dont remember either of mine having a bolt hole under the manifold !
You sure you have parts matched right ? We are talking about a 426 hemi aren't we ? Manifolds look wrong / best I can remember , show a pi of the whole manifold >>..

Yes, photos are from 426 hemi crate engine with original vintage 1968 cast iron exhaust manifolds bolted on. BTW, my original bare '68 heads are same.

 

[Runcharger]

Remember the right and left manifolds are different, I believe that's the reason for the extra holes. Otherwise you'd need different left and right heads. Anyone that has put together a 426 has wondered about this, it's the way it's supposed to be and nothing to worry about.

 

[not so famous bob]

Remember the right and left manifolds are different, I believe that's the reason for the extra holes. Otherwise you'd need different left and right heads. Anyone that has put together a 426 has wondered about this, it's the way it's supposed to be and nothing to worry about.

heads are the same side to side!

 

[doberjoe]

heads are the same side to side!

yes. Heads are same, side to side. And yes, exhaust manifolds are different side to side. Question is "what do I do with the empty, unused holes" in the heads? Fill them with stud below the flange surface, or leave them open? I'll grab some more picutres of bare heads and manifolds tonight at the shop.

 

[Fran Blacker]

If you feel better filling them, do it. I'd use 3/8" set screws length up to you. The set screws will be easy to remove if you want to. Sealer your call but don't use Loctite.