Heli coil need help

Why not go to the auto parts store and get a self tapping oversized drain plug. You can buy them in several sizes over, just like pistons. I have used these quite often and never had a problem.

I tried those twice $5 each did work for me.

Or Ken could have the correct tap on hand, make a very generous offer, and put this entire thing to rest.... Just like THAT^^^

Yip, I know a little something about this!
 
I had a stripped out oil plug on my lt250r. I went to auto zone and got a self tapping over sized plug was like $4, it was a little tricky to get it lined up right to cut the threads. Once the threads were in i had to cut the bolt b/c it was running into something in the tranny and wasnt going in all the way. But it works good now no leaks and holds tight and didnt have to slipt the cases just try and keep metal filings from gettin all in your bottom end. Heil coils work well but dont mess them up they are a huge pain to get back out if you can at all.