Antenna location

I figured I'd get some more opinions on moving my antenna from the mirror arm to the back of the sleeper. The truck is a W900 with 42" flattop, the antenna would be a center load, the distance from the antenna to the stacks would be approx 5'3". I've asked a couple of different shops and have been told it would work great and that it won't work worth a dern. I know there is a lot of drivers out there who have done this. I've known a couple who did and it worked good but they had bigger sleepers. I've been thinking about doing this for several years now and figure I might get around to it someday. Any info is appreciated.

 

I am thinking about using a stainless light mount with the top edge stuck up under the fiberglass roof cap that way the top would be mounted to the frame of the sleeper, then adding more support at the bottom since it would just be on the sheeting, and I don't want any problems since the antenna is pretty hefty and all but about 3-4"would be up above the cab in the wind. Of course I probably should have mentioned this before.

 

Appreciate the info, I do have a good meter so I'll definitely check that out, and the truck is all mine so I'll play around with it a little bit to see if I can get the ground good before do anything drastic. Again thank you.