Dont know about the motor but i would fit 2" lowering blocks, make sure your front is not binding anywhere and if you're running big block torsion bars, swap them out for 318 ones.
Have you tried different tyre pressures. I changed my slicks fron M/T to hoosier and the car wouldn't 60 ft less than 1.48, from advice here, i upped the pressure to 13 and it dropped to 1.43 straight away.
Mick