I only get the vibration at 20-60 kms, nothing higher or lower, had all wheels balanced, new tired put on, sway bar links changed, front end tight, new balljoints about 8 months ago, anyone have any other issues?

its in the middle, not really front or back, checked driveshaft and u-joints, tranny shop says everything is good to go,

??? im kinda puzzled.

Take driveshaft out and check ujoints. If they are good check to make sure driveshaft has no big dings in it from rocks.I`ve seen both of these problems a countless number of times. To correctly check ujoints you have to pull driveshaft but most places dont.

thanks, you could be right, for some reason i have dings and dangs on my muffler from the previous owner, maybe she did hit something undernieth,

I will have that checked.