I tweeked this carb to death. I checked the vacuum in gear. Changed the power valves as needed. I checked for vacuum leaks. Nothing found. I did put permatorque gaskets on over the winter. The old gaskets were permatorque also. After all the comments on low vacuum maybe thicker intake gaskets are in order even though I'm not finding any leaks . I found a pretty informative site for troubleshooting with a vacuum gage. Might be old news to you guys but it's new to me. All I ever looked for was a reading.
http://www.junkyardgenius.com/tools/vacgauge.html
Once I rule out a vacuum leak once and for all I'll go back and revisit the carb issues.