Stripped Spark plug help

Stripped spark plug question. Last night on the way home my #7 spark plug decided it no longer wanted to be part of my engine. I am curious as to how others have tackled trying to install a Heil coil in the #7 spot. Is there enough room to access it, if you remove the inner fender liner? I have also thought about removing the fender to gain access. Any input and advise would be appreciated.
Thanks in advance for any help.
Erik

Year, make, mileage...

#7 or #8..... Now that's some seriously limited space.

If it was me, I would pull the head.

150,000+ on the mileage, I would just go ahead and pull both heads, take them down to a local machine shop and have them checked over. New valve guide seals, have them skim the head. There's a specification for the correct finish on the head surface.

And at that point you get to decide how far you want to go. A lot of that depends on your intent for the vehicle. If this is an AFM engine, perfect time to delete. New lifters are easy to do at this point, with new lifter trays. (OEM lifter trays are mandatory here)

Any idea on the cause? Possibly over torqued, or cross threaded?

No clue as to the cause. Started up from a stop at a light and pop. I changed the plugs shortly after I purchased the truck. With NGK Iridium plugs. Maybe I did over tighten it. Not sure.

Too loose blows out plugs usually, if you over tightened enough to strip the threads it would have blown out a long time ago after you changed the plugs

I wouldn't over think it, pull the head and use a Timesert designed for aluminum heads (not a helicoil), the aluminum heads need a longer insert than the cast heads because the thread hole is deeper

If the engine ran good before I wouldn't start digging "while I'm in there", just install the timesert properly with loctite, clean up the surfaces & put the head back on

You will likely break a couple exhaust manifold bolts so get those out while the head is off & replace all the exhaust manifold bolts going back together

Good luck!