Here is a worthwhile thread:
http://forums.pelicanparts.com/911-engine-rebuilding-forum/596155-engine-dyno-north-nj.html
In the Bay Area, I would take my engine over to Jerry Woods Enterprises on the peninsula.
Jerry Woods Enterprises - Perserving Porsche Racing History One Car at a Time
In the late ‘70s, Jerry came to Denver to copy my engine dyno when he built his at Garretson Ent.
In the past 30+ years, he has had lots of practice.
I’m sure there are others within an easy drive but no one has more experience than Jerry.
Best,
Grady.