Sometime early in the 70s I saw two(maybe factory) 914-6s at Laguna Seca. I can't find a program and I do not know which race series it was. It was their first year on track and they were amazing. I think it was an under two liter series of some kind. It was the 9 turn configuration, so once they got out of turn nine, they were away and flat out all the way up the hill.
Any idea who the rivers were and what team sponsored them? It might have been a precursor to Brumos...
If they were orange and white they could have been from Art Bunker racing, the driver's probably were Bob Hindson and Ken Noah