Those look like the inserts I put in my "OLD Toyota aluminum head. The ones I used on the ole beater were titanium. After I put them in I never had an intake or exhaust leak on that head.

Now if they would make one for the exhaust side of the engine. I have an OS 70 Fs that had the exhaust pipe torn out. Almost all of the threads are gone. That is all O need to fix the engine.


Dru.