At least one of mine is stripped. How did you fix it? Tap out larger and make your own studs, or somehow sleeve it? Is there a consensus on this?
The best method is a Nut-Sert. It is a threaded bushing with retaining spikes. You over drill the hole as the kit states, counter sink lightly, tap to the size stated, install the sert. They are the cat's meow! Kar Products and others have them in a 5 per kit pack or even eBay has them in the 3/8 x 24 thread.
Be very careful when drilling oversize in any of the manifold stud holes - they're "blind holes" now but can soon not be !
Sorry Henry- as Steve mentioned, there is not a huge amount of material around the bosses in the water jacket. Because of this and the smaller tap drill required for a helicoil versus a nut sert or keensert, a helicoil would be the preferred repair method. Just a suggestion though.
Allen, be thankful that your car is wrong hand drive. On our right hand drive cars the steering column gets in the way, especially on the back hole. I made a special long drill and tap holder to get a helicoil into that hole so I didn't have to remove the steering column.
Allan from down under.
I think Henry is referring to a time sert. http://www.timesert.com/ If you do a web search they are available from many sources. Just be sure to get the correct thread size and pitch.