360 balance question

I'm confused. Deeply so.

I'm in the process of building up a 360 (numbers reveal it dates from '71-'74) from the block up. Aside from the block and heads, everything will be new. The crank is in, the cam is in, the pistons are in, and the heads are being worked on by the shop right now.

What I'm not sure of is the balancing act. I've read a lot of pages on how V8 engines are balanced in general, and I understand that more or less. I also found that the 360 is an externally balanced engine. But I'm not sure how to do that. I do not yet have a harmonic balancer, but I do have a steel flywheel I just bought from 440source.com, which you can check out here:

http://440source.com/flywheels.htm

But as I've peeped around the forums I see many members drilling three large holes in the flywheel to remove 19.75 ounces of weight in the correct places. I've taken note and copied the diagram for this. The question is, do I need to do this? My machinist looked at me funny when I asked him about it. Worse, I've been told by some that the only thing necessary to balance the engine is the balancer and a whole, unmodified flywheel.

I'm not at all sure what gives here.

I can tell you that I'm going to mate it to my A-833 manual gearbox and I have a centerforce clutch sitting in the box if that makes any difference.

Huh?