Milo writes: "4.)  Still no luck?  When in doubt, burn her out!  Get a
torch, being careful not to ignite any diesel laying on your engine in
pools (clean that off first!), and cook the heck out of the heat shield
in question.  Then, drop some ice cold water on it - hopefully that'll
pop it out."
>>>>>>>>>>>>>>>>>>>>>>>>>>

---hopefully it won't warp the head.
Heating then dousing the heat shields while they are in the head is an
extraordinarily bad idea.

Soak with a crud cutter (like WD-40, Bra-kleen, etc) and tap them gently
all around the periphery for about 2 minutes each. Then use the wood
screw idea.

G. Matthew Bulley
Co-Founder, Principal
Bulley-Hewlett, Corporate Communications
Mount Olive, NC
http://www.bulley-hewlett.com/
+1.919.658.1278