Will these pushrods work?

As to your question “where does the oil go when it dead ends in the rocker shaft” it doesn’t dead end. The rocker shaft has grooves cut in it that allow oil to lubricate the rockers and shafts. Also the “leaked” oil is “directed” to the tip of the rocker to cool the springs. If you are talking about the oil in the pushrod dead ending. It also weeps out between the rocker cup and pushrod.