[shavdog]

This is a recommendation for a repair...I have a ford 302 with alum. heads and damaged the threads as I was trying to replace a plug...best I could tell, I created a burr or folded over the beginning threads in the head...On the internet search I found a tool thats called a backtap...I bought a 14mm one from amazon.com for 23 plus shipping...this product was a wonderful fix for my problem...its pencil shaped and has four prongs that are in the colapsed position..you insert the tool all the way thru the head and then turn the adjuster to expand the prongs...go slow, put some grease on the threads and adust it tighter as you make more passes.....after about 5-7 passes, my threads were straightend out, the filings came out of the head and I could reinsert a new plug...this was like majic to me...work from the good threads to the bad ones...when this first happend all I could see was, have the engine half torn apart to risk not having filings in the cylinder and a helicoil inserted....keep this in mind if you ever have this problem...just do a google search for backtap 14mm and several will come up...mine was by powerbuilt distributed by amazon.com...craig

[matts37chev]

pic please

[LATECH]

NAPA has a helicoil for spark plug holes and it works well without removing the head. I have used it many times with great success, on many models.
Ford escorts used to have issues with the plugs coming outback in the 80s.I did a lot of those, mitsubishis and others aluminum heads as well.

[cobalt327]

Originally Posted by matts37chev

pic please

[sprecher48]

there are several companies that make an insert thread repair.once again,use grease on the tap,screw it into the head. be sure to blow it out with air,install the insert with locktite(in the kit) put in the plug and you're ready to go. these kits come in long or short reach and also come in several oversizes,in case you strip it the first try. i've used these for years in vw heads and had good luck with them. tom

[matts37chev]

Originally Posted by cobalt327

i have used both heli-coil and insert type spark repair stuff

and its a lot of work and i'm always worried about failure

for some minor repair/clean-up this tool looks very good to me