Small Block LA rocker shaft hold downs

There are no "right" or "left" rocker arms on a normal "LA" small block. All the rockers are the same. So that isn't possible.

Yes, there are right and left rocker arms on stock stamped steel small block LA engines... The ball for the pushrod is biased either right or left... The ball sockets should be opposite each other for a given set of valves (they point outward)...