I've used a Compu Car hat system & built my own system using a Vortex Billet throttle body spacer The hat on a 01' R/T Dak & the Bob built on a 98' SS/T
The Magnum itself will hold 150 when metered correctly with stock hard parts Finding that happy go lucky medium with a factory EFI system takes patience
Most have an over rich condition starting out due to air temp change in the keg when the spray is hit