Sounds right. The last one I bought from Uni-Thread Ltd in the UK. 7/16 X 18 BSF
kit is about 35 pounds so currently about $45 plus $10 shipping. Reasonable and the last one shipped to Massachusetts in a week. I was amazed.
I could not do this "in situ" I'm not taking this motor out again anytime soon! I'd rather plug the hole with JBWeld!
Curious. My thread gauge says my plug is 18 tpi. (Greg Marsh Fastener database says 18). Vendors show the part as 7/16 x 16
. (Can't find a helicoil kit for 7/16-16.)
Could this be the reason it is stripped?