Two options.
Stretch the clearance hole in the adapter plate to fit the new incorrectly placed hole in the block.

Drill the incorrectly placed hole in the block in the right place for a Heicoil only if it is close enough to correct with this method.

A possible 3rd method would be to put a bolt in the hole flush and start over. I don't like this one because the new hole will be partly in this repair, if the "plug" loosens it could jam and the bolt won't want to come out. I also think that it may not be as strong as it could be, depending on how much overlap, about 1/2 a diameter would be better than less.

Good luck,
Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-