This is a quick and simple rule that I have applied in the past to find out how a 5th wheel coach will interact with the rear of the TV cab.
1- Measure from the center of the fixed 5th wheel (where the Pin would sit in the 5th wheel)to the back of TV cab = A
2- Measure from the center of the coach 5th Wheel Pin to the outer edge of the front of the coach = B
If the measurement of B is less than A you will have clearance when on a 90 degree angle.
PS: if the 5th wheel has not yet been installed in the TV, you can then estimate by measuring from the centre of the rear axle to the back of the cab. A properly installed 5th wheel should be positioned centre on the axle in the TV box. When in doubt add a few extra inches.
GPG
