would blue loctite or star washers help keep the two nuts from turning?
Wobble extensions might also help here?

Are you certain there's no bolt remnants in the offending stud holes?

On 5/20/16, Don Hanson <dhanson928@gmail.com> wrote:

>....  I can get to all but
> two of  the exhaust manifold studs with box wrenches, but the two in the
> central cylinders I can only reach with multiple extensions and deep
> sockets while the motor is in the van....So...When I try to install those
> two central studs....It don't woik!    I've been counter-tightening two of
> the nuts, then running the stud down into the head, but I can't make it get
> tight...the two nuts will work down the stud and the threads on the stud
> won't thread far enough into the block to hold well...I

--
Neil n

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