PFF44-107 is made in our Purple 80A material and recommend for track use. A small increase in NVH, usually at idle, should be expected when stiffening the connecting mount between the engine/transmission and chassis. The harder the material used, the greater the NVH transmitted. Please check the size before ordering. PFF44-107 is 60mm in diameter, whilst PFF44-108 is 70.5mm in diameter.