Vibration in my truck?

Okay, I have a 1988 Ford Bronco. It has 150,000 miles on it. Here is my problem, It started not to long ago (couple weeks) when I get above about 50 mph and give it enough gas to keep the same speed, it vibrates very bad. Slower, it is fine. But when you go faster and give it just a little bit of gas, it shakes all over. Another Bronco we had a long time ago done something similar and it was caused by the torque converter. This could be the torque converter or maybe a Universal joint so I have been told. I just need to figure out what I need to have looked at. Thanks to anyone who can help me figure out whats wrong.