IMO....(and I can say this because I have every version of the Predator Antenna's ever made) You just can't beat the original Predator Single-Coil 10K when it comes to tuning and performance period...
I have known Kale now since around 2000, and the guy builds one heck of a antenna, and now at the young age of 84, he still hasn't lost his touch!
The Original single-coil 10K tunes the tallest, which is one reason I stick with it because you know the old saying, "Height is Might"...
But not everyone can run a 7 foot-plus tall antenna which is why Kale has the "Comp, Bad-2-the Bone, and the SW dual coil 10K's...and there is also a mini-coil 10K which has a coil thats only maybe a inch or 2 in diameter... and the 30K for those who are planning on running enough power to cause black-outs.
Trick to getting these things to tune low, is you have to keep it away from the cap and the coil section at least a foot above the roof...If mounting on Mirror brackets, that's not possible so you just have to make-do with what you have and hope for the best...Big Trucks have allot more problems getting any antenna to tune just because of the way they are built now days...
One idea that I had mounting my 10K on my Tacoma was to mount it on a riser mounted to the bed, to get the whole antenna roof-high, without having to drill a hole in the roof... Now there's plenty that say "This won't work, or it's not going to have the same signal pattern as a antenna mounted on the roof"...Well...I'm here to say..."BUNK"...
I have a bout as low a SWR as is possible, 1.0 to 1.1, X=0 on all but channels 1-6 which is X=1...I could probably get those channels to X=0, but figured I was close enough...According to my test results with my field strength meter I have sorta a figure 8 pattern where just about a equal amount of signal go's out the back and front...This is the same thing I was seeing with the antenna on a magnet mount sitting on the roof...My guess is the reason I don't get a more omni pattern is because the truck is short and narrow...
I did have to cut some off the stinger, like y'all did, but not as much, because my antenna is mounted so it's roof high...Where most mess-up is thinking the antenna only radiates a signal either from the tip of the stinger, or from the coil up...This is not true, the whole antenna radiates signal, so if the lower half of the antenna is up against the cab, your going to have reflect problems.