At home flywheel balance....

25 years ago I had drilled a flywheel at home myself to use behind a cast crank 440.
I didn't even use the correct recommended drill size from the Mopar bible.
Just calculated the space that was to be removed with the intended bit and converted the
volume to get the depth of the closest sized bit I had on hand. Even had a different degree cutting edge. Size and depth of holes were not to the print when done but the placement and volume of metal removed was. Used my drill press. Couldnt have done it without mopars instructions and a machinist hand book.
Worked great with no vibrations for years and still have it. Got plans to use it again on a different cast crank 440 engine soon. I drove it very hard without incident.
We are lucky that ma mopar makes this kind of info available. The handbook and a calculator is really usefull also for those of us that are mathematically challenged.
It really wasnt that scary then and I would do it again without any fear now that I have proven to myself the Mopar prints are sound.
Never welded to a flywheel before so I got nothing for ya there cept steel generally welds easy.