mechanical/adjustable lifters?

DrgnMazda is correct. It is very common to find engines that have had B2200 heads swapped or had the cylinder heads rebuilt and hydraulic lash adjusters installed. Importperformanceparts.net has the mechanical rocker arms for cheap. I think the entire set cost me $180. Be very careful with junkyard rocker arms, many of them are garbage from lack of maintenance and oil starvation, always use bearing caps that are installed on your head, they are machined to match. Swapping caps from another engine could cause permanent damage.