Ok... well i finally found out what the problem was and i'm ashamed at the stupidity of it, but i'll post it up anyways in case it might help someone in the future...
I tried everyone's suggestion... I grounded the antenna and the radio directly into the frame, bought and installed a spring, shortened the coaxial cable to almost exactly 18', and replaced the whole cable with better shielded cable i picked up at a truck stop... nothing worked. It all made it better, but i was still getting 8.5's an 10.5's on the swr test... I knew antenna trimming wouldn't fix a problem that big, so i knew it had to be something besides tuning! i checked the continuity between my antenna cable and the battery with a volt meter and i was at dang near perfect ground... but while i was testing this i accidentally touched the volt meter probes to the outer part of the male end (the ground) and the inner part (the power to the antenna) and it registered continuity... not good! I checked at the base of the antenna and again, i found that there was a connection where there shouldn't be... Upon further investigation i found it was due to faulty installation of the ball mount.
When i attached the ball mount to my fender a while back i neglected to read the directions where it said the middle hole should be an inch in diameter and not simply the width of the male connecter coming through the fender... this meant that my power was grounding out directly into the fender, and bypassing my antenna all together.
I drilled out the hole bigger so that the positive post would no longer touch the fender, slapped it back together, and WHAMOO... i had flat 1's across the board... and i immediately began to hear truckers from the interstate a couple miles away! It works great now and i have better reception than i've ever had before!
Thanks guys for all the responses and ideas!
Here's pics of the install:
