I think the factory recesses have vertical sides (it's kind of hard to cut a recess that's larger at the bottom than the top, but GM went the easy way). You may be able to use a flat punch and hammer to push the deformed metal back out enough to get the plugs in.


Kevin
1951 Chevy 3100 work truck
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1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.