This Spec 50oz aluminum flywheel is a great upgrade for your 1986-1995 Mustang with an internally balance engine. With a lightweight, aluminum design, this flywheel reduces rotational mass which helps your Fox Body or SN-95 Mustang accelerate faster. A great way to get more engine response from your 5.0 motor. Spec billet aluminum flywheels are machined to a .001 tolerance and are perfect for 50oz imbalance motors. SFI Certified.