Yes you should torque your lug nuts. Finding the value to use is problematic though. Here are some general recommendations stolen from another website:

Lug Size Ft/Lbs Torque
7/16" 55-65
1/2" 75-85
9/16" 95-115
5/8" 135-145
12mm 72-80
14mm 85-95

IMPORTANT NOTICE: As with all types of wheels retorque lug nuts after the first 25 miles & at 100 mile intervals until lug torque is maintained.
Note: Always refer to Owner's Manual for proper factory specifications that take precedence over the listed recommendations.

1953 Chevrolet 3600
Fried Green T'mater (Vern)
In the Stovebolt Gallery
Caution: Political Statement
Man who runs in front of car gets tired, man who runs behind car gets exhausted.