Never have done a helicoil install but I'm pretty confident. It needs to be installed on the right head. I'm making a guide for my drill so I don't **** it up, although the ac hoses might get in the way. Someone else said that some locations will not leak any oil without a bolt but I'm not trying to put everything back for it to leak.

 

Helicoil should be fine for the cover, but if there is enough meat to drill and the helicoil fails, consider EZ Lok.

See how the helicoil holds first.