great advice guys..... can't believe i didn't think of it already! 
especially since i already got a replacement tin, so if i cut the old
one out and notch the new one, i never even have to remove those
bolts!!

but i'd still kind of like to as a matter of principle.  would it be
easier to get these out if i ran the engine for awhile and let
everything get up to temperature??  i seem to recall that for any
given type of metal the size of a hole will increase more than the
size of a cylinder of equal diameter when subjected to an equal
increase in temperature.... true???

but then i guess i have to wait until i get my fuel injectors back...
they are presently out at cruizing performance getting cleaned &
serviced....

Ben.