Vibration at low speeds

My whole truck shakes between speeds of 25 and 35 or so mph. I know I have one bad engine mount, but I don't believe the problem is RPM related, since I can be coasting to a red light and kill the engine, and the shaking doesn't stop. Revving the engine while stopped is completely smooth. I ordered new upper and lower ball joints, a new idler arm and pitman arm, that stuff is supposed to arrive on Tuesday. I'm hoping that stuff helps when I get it in, but am I looking at something more serious? The front tires show cupping. I don't think it's wheel bearings, I've dealt with those before, but only on FWD Hondas.

post deleted

That doesn't help me, I'm not new to vehicle maintenance. What you're missing is that cupping on the tires indicates worn suspension components. What I'm asking (in a nutshell) is if this shaking is a common result of any of the worn items that I will soon be replacing, or if it's something more. I guess I'll just have to find out after I put the new parts on and have it aligned.

Balance your wheels!

Check your driveshaft u-joints. Mine did the same vibration at low speeds then eventually got worse, stupid me replaced the whole front end before I figured out the problem. Lol

shocks!!!!

post deleted

like he said u joints or possibly your pinion angle could be tweaked and youre getting diff hop??