95 formula, Driveshaft Vibration

The driveshaft in my formula has a terrible vibration starting at about 85mph. The whole car shakes. I had already replaced it with an aluminum shaft and that helped, but I just got a new engine installed and it is worse than ever before. What else can be done to fix this? Is the angle of the shaft out of alignment? :banghead:

could be that but what it also might be is the u-joints. My friend put some aftermarket u joints in hi 86' and the car had that same vibration around 80mph. Once he put OEM u-joint back in the car....wow magiclly no more vibration.....