WOW,
I prefer Ford to Chevy
The 350 is a shorter OAL so it works (factory loaded) in a shorter action. Its got an edge in velocities with bullets under 250.
The 35 Whelen fits in a standard action. It not as fat so you get up to a couple more rounds in the mag. Its better with bullets over 250.
Truth be told, its the difference between and S&%T and a Fart. IMHO looking at both on paper, there is not enough to worry about. In reality, strong arguments are made for each.
I prefer the 35 Whelen, the better feeding, more rounds in the magazine and better performance with heavy weights wins me over.
CW