Powerflex PFF85-504B Polyurethane Lower Engine Mount Insert Black Race Series Powerflex polyurethane replacement large lower engine mount insert. The insert fills the voids of the original bushes so limiting engine movement. Improvements include more effective power delivery to the wheels and crisper more defined gear changes, along with less stress for the exhaust down pipe. 95A durometer Powerflex Black Series bushing. All Powerflex products come with Manufacturer's Lifetime Warranty!