GM crate motor questions

[navyflyer72]

I recently bought a GM Performance crate motor, it came with oil dipstick holes on both sides of the block. I prefer to have it on the driver side so I put the oil tube there, the hole on the passenger side of the block (down near the starter) is too small for the little steel plugs that came with the engine. I tried sticking them in the freezer overnight and heating the hole with no success? Is there some other way to insert these plugs, or are they the wrong size for the passenger side opening? Ideas and suggestions appreciated.
-George