Rear drag shock settings

Just bought set of rear shocks for my street strip Duster. Comp Engineering 3 way adjustable drag shocks. I am going to 1/8 mile track this weekend and wanting setting on shocks to start out. Options are 50/50, 60/40, 70/30. Can anyone suggest setting to start with and will only get 3 test runs before elims. Duster is stock body, full interior, with 408 stroker @ 500 hp,, 727 auto, 3200 stall, 3.55 sure-grip, & MT drag radial slicks. I foot brake and leave line at 2000 rpm. Use pinion snubber and spring clamps. Usually hooks pretty well. Best w stock shocks 7.91 @ 90mph.