which threads in an engine block, if damaged, make it "toast"?

[amalventano at sc.rr.com (Allyn)]

> Could anyone tell which threads on the outside of the engine block
virtually ruin the block when damaged?

well, i did a rather quick weld/drill/tap on the all-too-typical a/c bracket
mount point snap-off syndrome:
http://scirocco.dhs.org/vw/pics/0-allyn/rieger/images/030305-234025-Z10.jpg
welded/drilled/repaired:
http://scirocco.dhs.org/vw/pics/incoming/images/030307-174854-Z18.jpg
not bad, considering i built that loop with weld-only.
worked like a champ as well.

as far as your other threaded holes, i would say you could safely
weld/drill/tap/otherwise repair any threads not involving a head or a
bearing. head/bearing threads can be repaired, but i would get a machine
shop to do it.

hth
Al