We were now ready to install the new serpentine belt. Magnuson includes a steel pin to lock down the tensioner, and it was necessary to use the pin to get the belt into position. We also slid the idler pulley all the way up and then slipped the belt on. It was at this point we slid the pulley back down and released the tension. The belt tension was extremely strong, which is exactly what you want from a supercharger kit to prevent any belt slippage.