This is in the same area as the three wedge tombs. Follow the track that leads to the east tomb, however rather than turn right at the farm-yard, continue through the old farmyard and when you are on the other side of it, the standing stone is on the left hand side about 50m away. Its not marked on the OS map and I havent checked the Tipp inventory but im pretty sure it is an authentic standing stone. Its approx about 0.5m high.
This is found by carrying on up the lane from west crowlands to the old abandoned farm-house. Just before the entrance to the farm there is a red gate, open this (its in bad repair so don't climb over) then there is a gap on the left. Go thru the gap and there are some low blackthorn trees on ur right. Enter the field on the other side of them and look across into the field next door you should be able to see the standing stone. From the stone it is easy to find the tomb.
There is very little left of the tomb but it seems to be perched on top of an unusual hill. There are the remains of a bank around it as well but this may be the remains of an old field system.
This tomb is situated on the bend of a track that can be clearly found on the OS map. The OS map suggests that you can possibly drive up the lane but there is a gate on it, so best to park outside. I met a guy who works on the land and he uses this lane in his landcruiser so try not and block it. The entrance to the lane comes after some turns on the main road coming from the rearcross direction.