NV3500 or NV4500 for C-30

[clemdaddy]

got a 1-ton dually with a 4-speed granny. has the big hump tunnel and all the original equipment and low-low gears. 60mph = 3200rpm

what are the pros and cons of the later five speed trans?

install difficulty? shifter location? hydraulic clutch conversion?
towing and highway driving benefits? which would you run, 3500 or 4500?

need to do this, the dually has become the daily.

thanks, clem