Les and Lester or Steve. Definitely

This photo, and

this one (calm down ladies), show Wayne Karcich. He says 'I'm a has been who never was', but is, in fact, the Gene Romero West Coast Vintage Champion 2008.

Anyway, he really got in touch to tell us that "I have a lot of old programs from the 70s. Those photos are from San Jose on the half mile in I'm guessing 71, 72 or 73. I think 11y is Lee Seidel. I will go to the shop and check on those 2 riders and get back to you with an answer.' Then he did to tell us 'My programs for that year show 11y as Les Costanza and 14z as Lester Horn. Both Northern California riders.'
And then 'Sorry for another email bother. An old timer here in the neighborhood says 11y is definitely Les Costanza but he says 14z is Steve Wilson from Half Moon Bay. So there is a controversy on 14z, either Lester Horn or Steve Wilson. It depends on the year of the picture.'
Cheers Wayne. We've got to get ourselves one of those neighborhood old timers.