On my 84 Vanagon the two studs that hold the lower alternator bracket
to the engine block have broken off (see Bentley page 27.15)

....and of course they've broken off behind the bracket aka inside
the engine block.  :(

In order to get access to the holes in the block I removed the
alternator, the metal coolant cross pipe from water pump housing to
the passenger side head then I removed the oil filler tube from the
bottom of the block.  (The oil filler tube is held on by two 13mm
nuts, one easy to get at, one not so easy).

Tomorrow I intend to drill out the two broken studs then re-tap them
with the standard 8mm threads.

How far into the block can I drill?
If I go too far I assume I will break the water jacket?   That
wouldn't be fun...

Anyone have a better solution?

If you've rigged up some other way to hold the lower alt bracket
please post photos....

-Paul