Oh maybe it helps with stability. A quality double roller will stretch but not by much. If it takes 100,000 miles in a daily driver to ruin a stock single chain how long will a double roller last in a street car driven only a few thousand miles a year? That's my take. The tensioner I installed was a Chrysler part and the tensioner blocks were narrow and apparently designed for a single chain. Not exactly cool. As the plastic material wears off where does it go? It does go through the oil pump before it gets to the filter. Your choice. I did it once but I probably won't again.
