kwikt

Is it really cracked by the temp sensor. Try inserting a feeler guage between the head/block in that area to see if it's warped or was dropped. If so I'd go the JB weld route.

Humboldtgrin

Just pull the helicoil out. It comes out all messed up, but it's done for so don't have any care about it.

Holytin

Use some "Belzona" super metal instead of JB Weld, best material available and the price is high. Not sure - I think we paid something like $400 for one KG. However, I might be able to get you some as long as you don't need a ton. Just pay for shipping. Send me a PM. Best,