I researched the issue knowing it must be something I was doing wrong. low and behold on cleveland tools website I found a very good explanation on what I was doing wrong, and a chart that helps with adjusting the gap setting for different rivet sizes. When the tool fails to set the rivet you must increase the gap setting slightly in order for the secondary cam to roll and achieve full setting force.
http://www.cleavelandtoolstore.com/prodinfo.asp?number=SNB214 Squeezer Setup & Troubleshooting - Solution to the "I can't squeeze a rivet" problem.
I went to the shop and set the gap according to the chart and the -6 was set with no issues. I adjusted slightly to achieve the correct shop head demensions. I continued to rivet the Fork and all went well.
The Cleveland chart mentions that the maximum AD4704 you can squeeze with the 214 is the -7. But when the plans called for the -8 rivets, I adjusted the gap according and these also set with no issues and look great.
