Well...try the ease-out (the cork-screw type if you can, and not the square type). I don't know what size would work yet.
Something else...since the block is steel and the fitting is brass you might be able to drill the center and re-tap the hole, then use cutting oil and air to clean out the hole. Brass is soft, and will yield to a tap made for steel...
just an idea.
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'69 3/4 ton C20 2wd w/ 350ci/400THM and a wood bed!
'69 3/4 ton Custom 20 2wd w/ ORIGINAL 350ci/4sp Manual and a wood bed (parts beast).
Seattle, WA.
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