Okay, comparing it to vehicles in Rites of Battle, your average Leman Russ would look like:
Type: Ground Vehicle
Tactical Speed: 10m
Cruising Speed: 35kph
Maneuvrability: -10
Size: Enormous
Armour: Front 50, Side 31, Rear 20
Crew: Gunner, Driver, 2 Sponson Gunners
Weapons:
Turret Mounted Battle Cannon (500m, S/-/-, 4d10+6 X, Pen 10, Clip 40, Blast 10)
3 Heavy Bolters (1 hull mounted, 2 sponsons)