First thing to do is the seafoam treatment, followed with a switch to synthetic motor oil. Hopefully this will stop the ticking as it will clean the lifters. As for the jumping at speed, does it feel like the engine is revving or losing power or is it more like the power not getting to the wheels, might be the tranny filter and fluid need changed or could be a bad sensor somewhere, like the throttle position sensor, usually though a bad sensor will give you a Check Engine light.