AFAIK, a '02 Silverado SS motor is a LQ9, not a LQ4. Easy way to check is to remove a spark plug and used a bore scope to look at the piston head. Flat top = LQ9, dished = LQ4. That's the only difference between the too, making the LQ4 have a CR ~9.4:1.
'98 Z28 M6 silver hardtop, intake, full exhaust, gears.