Thoughts on how to recover from a slightly cross threaded spark plug threads in head?

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beady

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Was installing a DUI distributor, coil, wires, and plugs. Got distributor and coil installed and old plugs out. Started installing new plugs and hit a snag.

454, #8 rearmost passenger side. Felt like it went in ok a few turns and then I started tightening with a ratchet, but it didn’t feel right so I stopped.

First thread of the new plug is a little rolled. Neither new plug nor old plug that came out will go in now past a turn or two, obviously I haven’t tried forcing it.

Pic of the new plug I tried to install attached, you can see the first thread is dicked up. There’s a little anti seize on it is why it looks odd.
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Thoughts/options?

Thanks
 
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Goldie Driver

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My first thought would be a tool like this from a local parts store.

Get the thread cleaned up and rock and roll !

 

beady

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My first thought would be a tool like this from a local parts store.

Get the thread cleaned up and rock and roll !

Is that deep enough/has enough clearance to get a socket on that hex and fit into the opening in the head?

I thought I read ppl saying those were too large in some cases.

I did pick up a 14x1.25 tap this evening, might order a single ended thread chaser before I try the tap though.
 

Truck82

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My first thought would be a tool like this from a local parts store.

Get the thread cleaned up and rock and roll !

^^Same^^

I have also installed a TimeSert in my dads truck
 

beady

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I just ordered a regular, tight clearance thread chaser and also a “back tap” which you insert to the good threads, expand, and back out. At least one person had luck on an iron head.

Back tap
 

Goldie Driver

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Is that deep enough/has enough clearance to get a socket on that hex and fit into the opening in the head?

I thought I read ppl saying those were too large in some cases.

I did pick up a 14x1.25 tap this evening, might order a single ended thread chaser before I try the tap though.

I bought something similar ( if not that one ) for Goldie but never used it. I THINK it will fit just like a plug socket but can't say for sure. Seems like it would be totally worthless if it did not.
 

Ricko1966

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Is that deep enough/has enough clearance to get a socket on that hex and fit into the opening in the head?

I thought I read ppl saying those were too large in some cases.

I did pick up a 14x1.25 tap this evening, might order a single ended thread chaser before I try the tap though.

Use a chaser. A tap is not first resort. A tap is designed to cut new threads,and will,not necessarily at the right angle and not necessarily at the right depth. Meaning you might run the tap mid thread through the remaining threads,which will substantially weaken the threads. Grease the chaser to collect the debris.
 

ChuckN

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It’s just how my brain works, but my first thought was “of course it had to be #8! It just couldn’t be #1 or 2”.

But, it is what it is. Looking forward to seeing how this comes out- keep us in the loop.
 

Robert Bare

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You should be able to do it with a rethreader. However, there were made for years, rethreaders that expanded. You push them in, expand it, then back it out. You see, it starts down in the good threads and backs out, cleaning/cutting the threads. I would bet now only old time mechanics and machine shops have them.
 
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tsgs84

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My first thought would be a tool like this from a local parts store.

Get the thread cleaned up and rock and roll !

I agree try a thread chaser not a thread tap
 

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