Its easier to remove & replace them as a pair, I find anyway.

If its ever going back in you will most likley need to replace  - front
engine mounts, and the rear transmission mount - replace the engine shocks
and bushings while its out - the difference will be noticable. consider
having the steering box resealed and replacing the steering linkage at the
same time, also check the idler arm bushings - these are all easy jobs when
theres nothing in the bay.

Also replace the front pump O ring and sealing ring on the transmission -
dime a dozen and they do leak. if your doing this, youll need a new front
transmission case gasket since the bellhousing has to be removed.