Purchased a 9U data rack to mount to the wall that weighs ~50lbs, and can support an additional ~200lbs inside it (https://tripplite.eaton.com/smartra...l-mount-rack-enclosure-cabinet-white~SRW9UDPW). I was looking at how to mount it, and the mounting bracket has 4 screw holes, 2 pairs that are 16" apart, but because there is a 2.75" separation between the pairs it means only 1 pair of 2 holes can really go into studs. If I put (2) 5/16 x 2" lag bolts into the bracket and studs, is that enough?
Alternatively I could put a 3/4" plywood backer board up that spans 3 studs and screw into that, but would prefer to avoid extra work/cost unless it is necessary.

Alternatively I could put a 3/4" plywood backer board up that spans 3 studs and screw into that, but would prefer to avoid extra work/cost unless it is necessary.

