Ideal 5th wheel plate location

sounds like you're re-creating a beverage trailer kind of setup, go check out a beverage truck take some measurements to start with. That way you can match wheelbase to the distance the kingpin is from the axle. Also since you're setting it up from scratch, pre-drill holes so you can remount the 5th wheel every couple inches in case you find you want it a little different later, then it's just a couple bolts to change it.

 

BTW, king pin position on trailer may be different too. 4x2 truck is usually short so on some trailers king pin may be installed too far and gap between trailer and sleeper may be very small

 

Just did a 379 short hood single axle. 215"wb. Plate centerline is 3" ahead of axle center. Also have a T800 single axle with a 200" wb ant that plate is directly centered over the axle. But that also has a set back steer axle. Both pull 5 car trailers, steer and ride well. Hope it helps