Need advice on suspension and brake upgrades

Heres mine , 71 duster ,kind of a budget build with mostly mopar factory stuff & some aftermarket. Rear 1" lower 6 leaf espo springs (tried hotchkiss , they sucked) heliwig tubular sway bar w/ poly bushings on sway bar only , c-body 11"rear drums , moser shortened bbp truck axles , 255/50/17 kumho ecsta tires on american racing wheels . Front 1.09 mopar torsion bars , helliwig tubular sway bar w/poly on sway bar only , 73 bbp disc brakes w/drilled and coated rotors and severe duty pads , boxed lower control arms , c-body tie rod adjusters , stock manual steering w/lower sector support , offset upper control arm bushings (gave +3.5 degrees positive castor) 225/50/17 tires (probably should have gone 215 because of needing to trim inside of front fenders and would parking lot steer easier) . Drives handles and stops great , but the only problem is a serious lack of traction with the shady dell ported eddie head 408:icon_fU::icon_fU::icon_fU::icon_fU: and the stiff suspension