valhalla360 wrote:
I've yet to see a drop of water with a squared off bottom.
Tapering the back of the 5er could make sense. Tapering the top of the truck right before it hits the front of the 5er...not so much.
Yes, it would be better if the boat was not square on either end. And no matter which end is pointed on the boat there will not be a big change in the wind resistance of the whole rig. But the flat at back will be too far from front of trailer to push air away, the trailer will be hitting more turbulence.
Also, the OP is wondering about loosing room back of cab/trailer, with just the rack. To mount the boat, the end must stick past that rack. The narrower the end, the closer it can ride to trailer without hitting. The more of the boat, flat or pointed, that sticks out past the windshield, the more air the windshield pushes up will be caught, so back will be better.