Identify this rail? New to me sled 3100 miles

[Acnas1]

Oem or aftermarket? I bought the sled used 2018 Srviper XtX I was going to install hygear rear suspension linkage kit. Circled is a reinforcement of some sort? The kit wants me to move the cross shaft back a inch. Shaft to move is at bumper area. To move cross shaft there is no place to mount the shaft back a inch? Not much material to dril a 5/16 hole. Also thinking of going to the Fox coil over shock for the rear... Calling Hygear tomorrow...Anyone run into this?