 96 cobra Transmisson, Drive shaft issue
Ok, I messed something up and I can figure out what. I changed my transmission mount and right away I now have a noticeable noise that sounds like a tire out of balance and a slight vibration in the floor that starts at about 45 mph. I have done a lot of work to the car over the last 6 months. But in the last month here is what as been done in order. New motor mounts ran fine after this. Clutch throwout bearing and clutch release lever, ran fine after this. New gears bearings ran fine after this. put 500 miles on it after the breaking period noticed a vibration at speeds above 95-100. Replaced the drive shaft seemed to do ok but still had a slight vibration at high speeds. Noticed that the transmission shaft was loose when I was replacing the drive shaft so two days later I was able to get a mountAnchor 2784. After doing this I had one sounded like a back fire/vibration/exhaust noise at high highway speeds and a slight shake in the floor board. Thought it was a exhaust noise so I had a shop put it up the lift today. No exhaust leaks. I'm really at a lost. All I did to change the mounts was loosed the two nuts on the mount. Took the two main bolts out of the cross member. I then had to take off the drivers side cross member mounting bracket to get it out of the way. Took the two bolts off the mount put the new one back on. Put the driver’s side cross member mount back on. Bolted the cross member back up. Tightened the two nuts on the mount and lowered the transmission. Did I miss something? I checked and all the bolts seem to be tight. Could something not be lined up right this is kicking my butt. Or also last night I noticed some sparks arching when the car was running at night with the hood open so I changed the spark plug wires. This made it run better but still got this weird noise.
Any ideas would help I have been under this car so much in the last week. It is really getting to me. | 
