the ls block and gsr block have the same deck height. Whatever crank you decide to use, use the rods to match it. (ex: gsr crank = gsr rods, ls crank = ls rods). Also be sure to use the corresponding rod bearings. They will differ. (You can use gsr rod bearings on ls rods but you have to modify the notches on the rod). The main bearings on both blocks are the same though.

For cliff notes version: yes you can use those parts in a ls block.

p.s. turn off caps lock before you work on your motor.