if your doing a BONE STOCK LS bottom end, use the GSR head so your compression will be higher. i think a LS bottom end with GSR head is 10:1. i would change the valves out to some flat faced Omnipowers to get it around 10.3:1 if you are staying all motor.

GSR head is a Better head than the B16. the old excuse "b16 head" flows better than a GSR is BULLSHIT. dont belive any of it