Thank you for the response.
It is a F-350 with a low service body. If I mounted on at top of rear window I would think it would be above the top of the cab with nothing behind it.
-Fred
Larsen KG-3E786UD, and have them install the mini-UHF connector for you.
786-846 MHz Glass Mount Antenna. Features 5/8 over 1/2 wave collinear design whip with Super Flex enclosed coil. Gain (dB) 3,Maximum Power 60(Watts), Mount
theantennafarm.com
If this is a work radio, and your employer supplied the radio, I'd talk to whoever does the radio programming for them and ask them about which radio shops they recommend.
A glass mount antenna can work fine, but you have to be careful where you mount it. You cannot place it over any defroster wires, or on some tinted glass.
A good shop can install a permanent mount NMO antenna on the roof of the truck. That'll give you better performance without the mounting challenges of the glass mounts. They'll also cut the coax to length and test everything out afterwards with their antenna analyzer.
It is not hard to install permanent NMO mounts on these trucks. I have an F350 at work with a service body and 3 NMO mount antennas on it, as well as a blade LTE/GPS/WiFi antenna. Full size American pickups are some of the easier vehicles to install in.