"Where no counsel is the people fall : but in the multitude on counellors there is safety" Let me ask a stupid question on the whole director, driven, reflector, thing. If hypothetically you could align all the elements correctly WITH NO BOOM would the antenna work correctly? In other words does the boom have any other purpose than to hold the elements?

In other words does the boom have any other purpose than to hold the elements?

Very very little. As you may note, the boom is usually mounted so that it has very little profile towards the transmitter.
Plastic (which bends over long spans) and fiberglass yagi booms are common.

I'm back. What should the gap dimension between the driven element halves be at 660 mgh be or does it matter?

It matters. Arent you using a Yagi Calculator like K7MEM or the free downloadable program "Yagi Calculator" ? They note the feed gap. :)

eldgreen, your balun question is now in the following thread for the benefit of all our members:

Baluns (Brands, Designs, Losses, DIY Loops, etc.) (http://www.digitalhome.ca/forum/showthread.php?t=100512)

can you stack 3 identical antennas or does lit have to be pairs?

Stacking 3 only gives a bit more gain than 2, if that at all due to matching problems. Its best to stack in 2's, 4's, 8's, 16's, 32's etc. After about a stack of 16, the amount of additional gain achieved is going to minimal for the effort involved.