There is generally no need to check top dead center unless the timing went out. The timing generally does not go out unless something pretty major happens and is really not part of doing a tune-up. Are you having a specific problem that you you are concerned about.
Motors today do not need " tune ups " like yesteryear.-----If you are having issues report the results of a compression test.----Starting problems on a " new to you motor " may be a procedure problem.