So i need a little help. I have a 22r/20r hybrid motor, when i pulled the 22r manifold off to replace it with the 20r one most of the threads in the wholes on the head were ruined. I chased the threads with a 10mm tap to avoid drilling, still have an exhaust leak. I'm either gonna go SAE thread, but what is a size up from from metric in SAE? And is Helicoil possible without removing the head? If anybody has done this, any help would be great

 

i have a 22re, had to helicoil my front-most stud. (it pulled out at proper torque)

it was no problem with my cordless drill, head in place. i got it from napa, as that pitch i remember having a hard time finding at any hardware store. $60, no leaks, no regrets.

not a big fan of puting different sized bolts because of the amount of "meat" left to thread into deminishes. I realize that is also true with a helicoil but in my mind having the stainless insert makes up for it in an aluminum piece. mine holds torque like a champ. just watch some vids on it to make sure and do the proper install

btw that 60 dollar kit came with drill, tap, coil insert tool, and like 10 coils