Cool, another truck build. I have a www.gearvendors.com
overdrive on my Vette. It works well. They make them for just about any vehicle I think.
'03 Freightliner FL112, 295" wheel base, with '03 United Specialties 26' living quarters, single screw, Cat C12 430 h/p 1650 torque, Eaton 10speed , 3.42 rear axle ratio