As mentioned in my fieldnotes for the Cerrig Cyfammod Glyndwr I unfortunately ran out of time to see either these stones or the pair at SN7808489441. The pull of the high places simply proved too great. However Coflein has this to say:
'Remains of a stone row situated within open moorland, below Banc Llechwedd-Mawr and above the Afon Hyddgen. The four stones are aligned from north-east to south-west, the row measuring 6.5m in length overall and decreasing in size from the largest on the south-west. The largest stone measures 0.8m in height, 0.6m in length and 0.5m in width. The next stone has fallen, its neighbour measures 0.4m in height and the smallest, that on the north-east, measures 0.1m in height. Source: Cadw scheduling description. F.Foster/RCAHMW 01.12.2005'
I would suggest an approach something like as described in the aforementioned field notes is the best bet, the row lying a little to the approx south-west of the Cerrig Cyfammod Glyndwr. At least according to my map. Happy hunting.