Jim,
Do you offer a tap and die to clean-up glow plugs and head threads? The 1/4" x 32 thread is not a standard size at the local ACE hardware, I though you had a tool for this. Please let me know.

Best,   DennisT

Like this? 

https://smile.amazon.com/32-UNEF-FLUTE-BOTTOM-TAP/dp/B079ZBC2BJ/ref=sr_1_2?crid=1XUVN4J6PH0AI&keywords=1%2F4+x+32+tap&qid=1560185264&s=gateway&sprefix=tap+1%2F4+x+32%2Caps%2C200&sr=8-2

McMaster has 'em.  Kinda spendy, but 1/4-32 is a specialty.

McMaster is a bit extra expensive, but you'll always get the best from them.

I wouldn't try to clean up a glow plug thread -- if the thread's bunged, just pitch it and replace it.

Dennis
I could buy a tap and die from one of the tool suppliers and resell it to you, but you would be better off to buy it yourself....      Or to answer your question, No I don't have those to sell.   Sometimes a new head is not an option and helicoil is required....   that is whole different thing....
Jim