yes there is a difference. LQ9 comes with more hp, and tq. It has flat top pistons giving you more compression. It comes in the 03+ ss silverado, VHO, VMAX, Caddy esclade. Depends on which lq4 you get for the hp ratings. I love my lq9.
so u suggest to get a lq9 not a lq4 ???
5.3 ext cab fully bolton eber tune ....13.5@ 103mph cant get better than that .