Removing 383 HP ex. manifolds. Suggestions?

[71 SE3834V]

Pulled the engine out of my '71 and ran into the first snag. The last bolt (shoulder bolt?) on the drivers side exhaust manifold is rusted off. Does this have to be drilled out?
Also the last 2 on the passenger side (shoulder bolts again?) are pretty thin. Is this a long hollow nut, so to speak, on a stud or is it actually a shoulder bolt going into the head.
What's the best way to go after this? I have torches and usually have no problem heating up ex. nuts (pipes came off no prob. w/heat). Should I just heat up and try to remove or maybe heat it up and let it cool down to expand and contract the stud and nut. Sprayed everything w/PB Blaster all ready and will let it sit overnight.

[71 SE3834V]

Thin bolt/nut, whatever?  

If this is a long "nut" going onto a stud will I be able to get it hot enough to expand it from the stud by heating just the end. Or is it a bolt going into the head? Looking at a picture in the How to Rebuild BB Mopar Engines it looks like a long nut.

[A383Wing]

it's a long nut (maybe 2" long) screwing on to the stud.....all studs in the head are the same length....

[71 SE3834V]

Ok, so now I know what I'm working with do you any experience/tips removing them?

[A383Wing]

all the ones I ever removed always broke the stud off in the head.....not sure what you are gonna grab what's left of those nuts with seeing as you don't have much material to work with there.....

heat ain't gonna get to where you want it to go, the "nut" is long and bottoms out deep in the manifold....will have to think on this one

[71 SE3834V]

My whole project is on hold until the manifolds come off. I could start stripping the top end but what's the point if I can't get them off.
I did have success last year removing the heater hose fitting that didn't want to budge by heating up around it and letting it cool down adding PB Blaster as it cooled. When cool it popped loose and came right out. I believe it expanded and contracted and pulled the Blaster in.

[A383Wing]

maybe wire feed weld the hole shut in that nut and see if it will come off with a socket....I would not try a socket or a wrench on what I see above.....do all 3 look like that?

[ws23rt]

My thought is to find a drill bit the same size as the hole in the nut and drill a starting dent in the stud. Then with a smaller bit drill about as deep as the nut is long and finish drilling with the full size bit.

Now heat through the hole till red and let it cool than pb blaster.  Grind off the shank of the full size drill bit and put it in the hole for support leaving some to grab if needed and use a six point socket.

If all this fails than finish drilling with a larger bit.

[b5blue]

At this point I recommend buying all new studs and nuts as a set. Use the new stuff to gauge depth carefully so ya don't do harm to the heads. (The studs all go into the water jacket.) Your plan sounds good just don't go deep. 

[71 SE3834V]

maybe wire feed weld the hole shut in that nut and see if it will come off with a socket....I would not try a socket or a wrench on what I see above.....do all 3 look like that?

Wing,
The first 2 pics are the one on the drivers side. Completely rusted off. Nothing there. I'm thinking I'll have to drill the remainder of the nut a little at a time until the manifold comes loose (leaving other nuts on loosely to hold it). Then I should have enough stud left to grab with a vise grip and remove after heating around it. I have had success with that in the past on old snowplow trucks that the nuts were so rusted there was nothing left so I cut 'em off but that was on small block Chevys & Fords so easy to get to the nuts.

The 3rd pic is the rear one on the passenger side. The other one on the pass. side is a little thicker.
Right now I have the engine tilted slightly, pass. side up, on the stand & hanging from the lift so the Blaster will run into the stud. Will leave it another night.

[71 SE3834V]

My thought is to find a drill bit the same size as the hole in the nut and drill a starting dent in the stud. Then with a smaller bit drill about as deep as the nut is long and finish drilling with the full size bit.

Now heat through the hole till red and let it cool than pb blaster.  Grind off the shank of the full size drill bit and put it in the hole for support leaving some to grab if needed and use a six point socket.

If all this fails than finish drilling with a larger bit.

If I understand what you're saying after I drill w/the full size bit I will then have a hollowed out stud as deep as the nut was. So you're thinking that after heating in the hole the threads will break loose? Seems like it would be pretty weak to break the threads loose but that would be ok cause if it breaks it should break at the hollow leaving enough to grab hold of as I said above. I'm pretty confident I can get a broken stud out if I have enough to grab a hold of.

[ws23rt]

My thought is to find a drill bit the same size as the hole in the nut and drill a starting dent in the stud. Then with a smaller bit drill about as deep as the nut is long and finish drilling with the full size bit.

Now heat through the hole till red and let it cool than pb blaster.  Grind off the shank of the full size drill bit and put it in the hole for support leaving some to grab if needed and use a six point socket.

If all this fails than finish drilling with a larger bit.

If I understand what you're saying after I drill w/the full size bit I will then have a hollowed out stud as deep as the nut was. So you're thinking that after heating in the hole the threads will break loose? Seems like it would be pretty weak to break the threads loose but that would be ok cause if it breaks it should break at the hollow leaving enough to grab hold of as I said above. I'm pretty confident I can get a broken stud out if I have enough to grab a hold of.

You are right.  My thinking is that drilling the stud out to a tube will relieve most of the stress in the threads.  And if it breaks off so what the manifold comes off and their is a good grip left of the stud to remove it as well. 
I'm sure you expected the nut and stud to be toast to begin with and as B5blue mentioned you need new ones anyway.

Oh and by the way it's my experience that with a tricky problem like this a short cut just to see what happens might work but it also might change the whole deal into a different one that's less attractive.  And as B5 said drilling to deep is a risk you don't need and there is no value either.

[A383Wing]

I would have to go look at my new longer nuts I have in the garage, are they hollow all the way through except the nut head?

[ws23rt]

I would have to go look at my new longer nuts I have in the garage, are they hollow all the way through except the nut head?

I looked for one my self out of curiosity but didn't find one.  I know I have a few but my filing system--this pile and that pile---need improvement.
If they are not hollow all the way through it just means a few more drill shavings.  Let us know if you find one and how long it is.

[A383Wing]

OK, I went and looked at mine....I have all 3 sizes here....they are hollow only half way to the end....so what ever length you have, it's solid from the nut end to half way the total length of this special nut

[ws23rt]

  I would have guessed it to be hollow all the way

[A383Wing]

me too, but now that I think about it, it would not be very strong and it would twist like a fuel line would if tightened to much

[71 SE3834V]

Are you guys talking about new ones or old ones cause my old ones are hollow all the way to the end. I have filled the unbroken ones up w/blaster a few times hoping it will soak in and help.
I have had a lot of experience dealing rusty nuts & bolts on old snowplow truck and have a good feel for "how much is too much force" which is why I go to heating first but this is a new one for me. I have a feeling I'm going to be drilling all 3.
Where do you get replacements? Mopar Performance, Dealer?
I've had the 2 front nuts off of each manifold and they're in remarkable shape and the other ones look pretty good. Not rusted away like the manifold to pipe nuts.

[A383Wing]

all of my spares here are new ones...never installed....I ferget where I got them from..maybe dealer or Year One back in the late 70's or 80's.....any Mopar parts house has these..you just need to know the length

Year One, BE&A Parts, Mega Parts, Charger Specialties...any places like listed here should have them

drilling may be a problem once you get the tip of the drill bit at the end of the stud....there will still be some of the "nut's shoulder" left on the stud and holding the manifold on....drilling is gonna require going all the way to the head while manifold is still on....if that was understandable

[71 SE3834V]

Success! So far.

All the regular bolts came loose easily which I figured they would. Tried the thicker "long" bolt on the pass. side first. Tapped on a 13mm, 6pt socket  instead of the usual 9/16". It popped right loose. That gave me some hope.
A 1/2" socket (6pt) fit best on the "thinner" bolt. It popped but would only move about 1/8 turn. Sprayed it again and worked it back and forth but wasn't gaining anything on it. Let it sit while I removed some other parts.
Came back to it but it still wouldn't move any more. Decided to put some heat on it. Got the end red and let it cool back down adding PB Blaster. Tried again still nothing. Felt I couldn't heat it up and try right away as the end of nut was coming apart. Tried to weld it up. My attempt sucked so I got the drill out and put a starter dent in the center. Since I was looking at drilling I figured I'd try a little more force. I put a 1/2" bar on it, choking up on it and started to gain on it and worked it off. The stud came out of the head but that's fine with me. How the end of the bolt held together I'll never know. Must be a high grade.

Now I just got the broken off one to deal with. I know now the bolt isn't hollow all he way through. Why in the world did they make these partly hollow? What's the point in that? It's only going to collect crap (i.e. salt here in the north) and corrode faster.

[71 SE3834V]

all of my spares here are new ones...never installed....I ferget where I got them from..maybe dealer or Year One back in the late 70's or 80's.....any Mopar parts house has these..you just need to know the length

Year One, BE&A Parts, Mega Parts, Charger Specialties...any places like listed here should have them

drilling may be a problem once you get the tip of the drill bit at the end of the stud....there will still be some of the "nut's shoulder" left on the stud and holding the manifold on....drilling is gonna require going all the way to the head while manifold is still on....if that was understandable

Thanks for the info. I have a dealer close so I'll try that as well as looking around the net. I've got some time before i need them.
I figured there would be "shoulder" left. Now that I have 2 off I measured how deep I would have to drill to get all the nut. I'll drill a centering hole, then a pilot hole, then use a bit the same diameter as the bolt. I will be drilling some of the stud away but if I don't go too far I shouldn't get into the manifold flange.

[A383Wing]

the stud goes into the threads on the nut....once installed, no "crap" is gonna get in there. You will just have a small hollow section from end of stud inside.

Again, not sure how drilling is gonna get the nut off the stud since it goes all the way to manifold flange

[ws23rt]

all of my spares here are new ones...never installed....I ferget where I got them from..maybe dealer or Year One back in the late 70's or 80's.....any Mopar parts house has these..you just need to know the length

Year One, BE&A Parts, Mega Parts, Charger Specialties...any places like listed here should have them

drilling may be a problem once you get the tip of the drill bit at the end of the stud....there will still be some of the "nut's shoulder" left on the stud and holding the manifold on....drilling is gonna require going all the way to the head while manifold is still on....if that was understandable

Thanks for the info. I have a dealer close so I'll try that as well as looking around the net. I've got some time before i need them.
I figured there would be "shoulder" left. Now that I have 2 off I measured how deep I would have to drill to get all the nut. I'll drill a centering hole, then a pilot hole, then use a bit the same diameter as the bolt. I will be drilling some of the stud away but if I don't go too far I shouldn't get into the manifold flange.

congrats on making head way.   I agree with you---why make the long nut hollow to begin with

[ws23rt]

the stud goes into the threads on the nut....once installed, no "crap" is gonna get in there. You will just have a small hollow section from end of stud inside.

Again, not sure how drilling is gonna get the nut off the stud since it goes all the way to manifold flange

I see drilling to  the depth where the nut seats as a first step. If the drill size is large enough the only thing left holding is a thin tube of threads.  This should be easy to break off if not unscrew from the nut and leave a stub of the stud that can be grabbed after the manifold is off.
I tend to go at these things in a step by step way without blocking myself for the next step.

[A383Wing]

look at a new nut...it's not that thin around the threads...the nut seats against the manifold flange...about 1/2" past the end of the stud coming out of the manifold hole.....I'm afraid if he starts drilling, he may either go off center and break the bit off in there and jamb it against the inside of the manifold hole.