92 Celica GT Vibration

[1970_s30]

I have a 92 GT Celica with 197000 miles, runs great and just passed CA smog with flying colors today. It's been a great car with no major issues since day one.
Problem#1: Just recently started experiencing a serious vibration. It only occurs during idling between 980 - 1000 RPMs. The entire car vibrates. What could be causing this? Vibration is not an issue while driving and revving through the power band.

Problem#2

Just changed my tranny which came off a Camry and now my speedo is way off. Actual speed of 65mph reflects 85 on the speedometer. How can I fix this? Will this be easy to remedy?

Question: I also had serious oil leakage between the oil cooling sandwich adapter that the oil filter screws on to. It was leaking between the the cooling adapter and engine block. I took it off and put some gasket sealer on it which has held up pretty good, no more oil leak. What is that oil cooling sandwich called?...went to Kragen and Autozone and no one could tell me what that part was called. I would like to get the right gasket that is supposed to be replaced...just need to know what I need to ask for.

thanks for the help.

[vantheu]

Hey,
I had the same problem with 90 gts, found out i had bad motor mounts. I replaced all (4) motor mounts...no more problems...