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went to change plugs bad threds in head got any ideas

helicoil is the way to go. There was a post about it not long ago and how to use a shop vac to blow all the chips out of the combustion chamber so there would be no need to remove the head. Another way is to stuff pantyhose in there they will catch all the chips. I would personally probably pull the head to do it just so I am sure.

Helicoil. Have a dealer do it if you're a little leery. Should'nt cost very much.

I took the head off my 68 John Deere 8 hp went to the tractor shop they charged me $5 for the job total.

Heres that link The Dog33 was talking about

Spark plug screw up

...many moons ago when I was turning wrenches, KD used to make a combination reamer and tap for installing steel thread sleeves in damaged aluminum plug holes....these were much better than a heli-coil, since they were solid sleeves.....the tool oversized the plug hole (of course you had to be sure that the piston was down) and cut new threads....once the newly threaded hole was cleaned, the sleeve was installed on the plug (grease on the plug threads and loctite on the sleeve's outer threads).....I have no idea if KD is still in business, but you might check with an old import car mechanic and see if you can find the tool and correct sleeves...

That is also a good repair but helicoil is a better move. They work better and tend to stay put better. That solid sleeve is still available and used only where the hole is damaged too badly to use the coil.

We had a '69 VW bus with aluminum heads. First time my Dad removed a plug, threads came with it. He had a shop do the threaded sleeve thing. Next time he pulled a plug, sleeve came out with it.

The mechanic must have forgotten: oil on the plug threads; loctite on the sleeve threads....I bet I installed 40 or 50 of them in volkswagens....and they stayed in the head when the plugs were pulled..

They do normally stay in but not always. Common on VW bugs back in the day. The plug were tough to get at and hard to be sure they were threaded in straight. I used to buy them and off road them back when I was buying them for $25 to $300 a pop. Just another observation with those, tended to break the front tranny mount if you get them too high in the air off of jumps.