partitions

hello: maybe someone can help me.:clap: I need to get into compliance an existing 1 hour UL fire rated wall. The wall was made out with 6",20 gauge studs [email protected] 5/8" drywall 1 X on each side, 5" insulation. I been told by engineers to add 2- 5/8" on each side but I need to put in the PLANS...