904 freshening ?

If it was me,I would have some one open it up and check and or replace the seals and install a shift kit and a higher stall convertor.Over time,seals can dry and crack,and stick,this is why you start and run motors and trannys every month when not in use.Its cheap insurance to have it checked,and not have it fail, if you install it with out checking it after 8 1/2 years,Mrmopartech