TRACTION NEEDED!! 69short bed

[Dans69]

Running 650 horse 496, turbo 400, 3500 stall, 4.10 gear. Built rear w welded axle tubes and strange axles. Have 295/65 15 drag radials on street and 28-10.5 slicks for track. Installing Moser boxed trailing arms and new thicker panhard bar. Front lowered 3" w spindles and springs , rear lowered 3" with springs. QUESTION IS , what kind of rear shock and spring set up would yall recommend. My racing experience has been with 1st gen Camaros, 71 Chevelle, and LS1 F bodies. Advice appreciated!!!! Im new to the forum. But have used info from it while putting truck together over the last 2 years. p.s. using 200lbs rear ballast. Lightened front end with deleted bumper with a roll pan and fiberglass hood.