Engine Pro PB1004SS SFI Damper for 1964-2003 318 340 LA & MagnumENGINE PRO SFI DAMPER SBM 64 03 273 360 LA & MAGNUM INTEXT BAL 7. 3 OD STREET PERFORMANCE BALANCERS are the perfect choice for race classes that require an O. E. type balancer. They are also an economical choice for high powered street engines. SFI RACE SERIES BALANCERS bring the advantage of bonded balancers to high revving race and street race applications where an SFI approved balancer is required. The steel inertia ring positively protects against