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

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.

Thoughts/options?

Thanks

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

Get the thread cleaned up and rock and roll !

Goldie Driver said:

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

Get the thread cleaned up and rock and roll !

Duralast 14mm and 18mm Thread Chaser

Shop for Duralast 14mm and 18mm Thread Chaser with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

Click to expand...

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.

Goldie Driver said:

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

Get the thread cleaned up and rock and roll !

Duralast 14mm and 18mm Thread Chaser

Shop for Duralast 14mm and 18mm Thread Chaser with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

Click to expand...

^^Same^^

I have also installed a TimeSert in my dads truck

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

beady said:

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.

Click to expand...

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.

beady said:

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.

Click to expand...

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.

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.

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.

Goldie Driver said:

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

Get the thread cleaned up and rock and roll !

Duralast 14mm and 18mm Thread Chaser

Shop for Duralast 14mm and 18mm Thread Chaser with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

Click to expand...

I agree try a thread chaser not a thread tap

All good advice here.
One additional thing I do is put the engine on exhaust stroke and put an open airline in the exhaust pipe so any trash is blown out.