That's a good thing to do while the suspension is disassembled and floor is removed. It is nice to have extra tunnel clearance in that area. If you measure carefully you can get a loop coped into the existing rectangle tube section of the cross member.
I went 1-5/8 on my charger due to this being a structural section. You have to be careful not to intrude into the seat placement or pedal box when doing a tunnel mod. Nothing worse than aedal box for size 6 feet lol.
