My F-350 has the ball right over the rear axle. Works just fine. By the way it's a long wheel base crew cab dually.

'36 Tall cab Chevy 1.5 ton, '36 Low cab Chevy 1.5 ton, '53 GMC 2 ton, '51 GMC 640 5 ton, '47 Dodge 2 ton, '42 GMC CCKW 353 6X6.