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Discussion Starter #1
I'm working on a friends 283 SB and he has some studs pulling out of the bosses. Any way to fix it without pulling the heads? I know about pinning them like in the old days. But I heard that there may be a stud that has 3/8-24 threads on the top, and 3/8-16 threads on the bottom without the hex for tightening. I'd like to fix it in the car without pulling the heads. I'd be changing all 16. I have a tool to pull the studs out. Thanks in advance. Dave
 

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i would be very leery of atempting the job
on the car... drill chips/debris would be hard to
contain with the head on the engine.

i tried to locate the special piloted tap that's
used for the procedure a while back but couldn't
locate a source.

the stud's geometry is extremely important
and if the stud isn't installed perfectly straight
you'll find the guides/valves can be wiped out
real quick.

the machine shop might be able to source you
on the special 3/8-24 piloted tap... i wouldn't
try the job without one... they may not even use
a special tap depending on the machine process
used... i'd still inquire and see if they can source
you.

either way, pinning a std style oversized press in stud
or tapping for a screw in stud... it'd be best to remove
the head....
 

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The time you spend leaning over the fenders verse pulling the heads, pulling the heads is easiest.

Also rocker arm alignment and metal shaving alone is not worth the chance.

Pull the heads and have them done correctly.

IMHO
Al
 

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Discussion Starter #4
Thanks for the quick responses. Still figuring out what to do. Dave
 

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Hello,

I dont think that a stud with 3/8 threads on the lower portion would do you any good as the hole is already 3/8 and that is about the right size for taping a 7/16 thread.

There is a common 7/16 lower-3/8 upper rocker stud available, I think its origin was a 289 solid lifter Ford. I have installed a lot of these over the years but I much prefer the stud with intergal jam nut.

You can tap the stud hole on the car accuratly if you use a tap block that aligns on the adjacent stud and aligns the tap.

Another fix that I use is to ream the stud hole .003" and install oversize studs. I used to have to a lot of this but not much any more. I do have a bunch of both style of studs.

If you "must" do it on the car, debris is not really an issue if you use grease on the tap, and use care.

I would "prefer" to pull the heads, but that can open a can of worms.


Any Idea on why the studs are suddenly pulling? Usually there is a reason and itr might effect the the new studs as well?
 

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I did that to a Ford 360 engine before. I cut a small hole in a throw away paper cup and pushed it down over the stud boss on the head. Drilled and tapped it and put one threaded stud (without hex head)in and vacuumed the cup out.
 

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Discussion Starter #7
Thanks for the replies. I found a stud from Pioneer and Dorman with 3/8 top and 7/16 bottom. You guys were right and the hole should be right to tap a 7/16. And we have plenty of time to do it. Car has 42000 on it and hasn't been driven in about 5-6 years. Dave
 

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Thanks for the replies. I found a stud from Pioneer and Dorman with 3/8 top and 7/16 bottom. You guys were right and the hole should be right to tap a 7/16. And we have plenty of time to do it. Car has 42000 on it and hasn't been driven in about 5-6 years. Dave
Also Mr Gasket # 1071
 

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Hello

Its fairly easy to make a tap guide if you have an accurate drill press and some material adout an inch thick. You can probably use a guide plate for a lay out tool.

In my experience after i pull the studs i champher the stud hole with a fairly generous champher and this seems to help the tap start.

I also use an old poly lock to tighten the stud.i prefer loctite red stud locker to retain and seal the threads. They will leak coolant if they are not sealed.

Good luck

Jeff
 
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