I have one also that posted on here last fall trying to figure it out . Same block # with date code L 21 5 ( Dec, 21, 1955). Has 3 different mounting options. Front timing cover support like our old trucks use, side mounts and the angle front side mounts like used on Canadian Pontiac cars. Had no oil filter on it. I did drive the dowel pin in and installed a full flow filter. works great. Also has the two different throttle mount positions.
