The problem with running a oil with higher viscosity than recommended is todays engines are not your fathers engines. The internal tolerances are much tighter than those built 50 years ago. The rod bearings in your V10 Std Size Oil Clearance: 0.0011/0.0023 in. main bearing oil clearance 0.0001 - 0.0018. When you run a higher viscosity oil you don't get proper lubrication.
But you can run what ever you want in your engine I won't have to pay any money for repairs. I would run Mobil 1 0-20 if it was my engine.
Bill