I would suggest that yoy go to btetree.org and download. Start in the late 60 and move forward. Some very interesting changes occur.
A few I like,
6/10/73- I think I have these dates right. 4 set marathon that ends with Dicky Betts and Jerry playing together.
11/14/73- Truckin-The Other One- Big River-The Other One-Wharf Rat- Me and My Uncle. I think this is part of the second set. It really smokes.
77 Tour- So many good shows. For free you can download Barton Hall. Yes it is overhyped but is an excellent show. I just love Estimated Prophet on this entire tour.
9/2/78- One one disc you can get Good Lovin, Scarlet Begonias-Fire on the Mountain. Sound quality is a B. This is my favorite Scarlet-Fire.
Finally, I would suggest you download some of the Grisman-Garcia show. Both the Warfield and the Squaw Valley shows are great.
Happy listening