This is probably a typo on the tape and is more likely to be UC San Diego 1974. The Grape played Santa Monica Civic the previous day and is the only show listed at the concert database for 1974. The Santa Monica show probably wasn't taped, but the poster is below
I attended a Moby Grape show in National City (suburb of San Diego, big
sailor hangout) on August 8, 1974. I remember the date because we watched
Nixon resign on television before going to the show. They were great. It
was the line-up with Johnny Craviotto on drums and Jeff Blackburn in the
Skip spot. I remember JC singing a great version of Gone Dead Train and
Mosely rocked Goin' Down.
Also, for the very first time since it was aired 12 years ago, VH1, Where Are They Now - Moby Grape segment from 2000.
For people that don't know the history of Moby Grape and their start in San Francisco, this is worth a watch (Moby Grape did win their rights back in 2006, 6 years after this was aired, which is why you can buy official live albums on Sundazed now for the first time). The Grape also played last night, July 29, 2012, at Louiefest in Tacoma