Wondering if anyone can tell me what I need to do to drill a pilot bushing

Well, when I drilled mine out the input shaft had already been hacked on a little to fit in an auto hole.
So I used a bearing.
Car won't see that many miles and Brewer's sells a quality one.
I used a piece of angle iron across the flywheel with an appropriate size piece of pipe welded to it for a guide.
Someone said the cast cranks can be porous and can seep.
I coated the inside of the hole and the shaft doesn't touch the crank hole, in theory.