You have had experience in both technical and managerial post.
Between these two, You sure must have found the difference.
Sit in a calm place and ponder which job gave you satisfaction.

If you like managerial post, well you have a easy job, its easy to pass an interview.
Tune up your communication skill and sharpen your decision-making ability.

If you had enjoyed technical faculty post, you need to work-up on various aspects, since you have had 2 year break, you may be asked to provide valid reason for the same.
Secondly technology has advanced a lot more than you were in-touch with it over may be over 3 years ago...
You will have to keep up-to-date and catch-up with latest technologies.
Since you are experienced your technical interview will be tougher than usual ones.