I'd replaced the 2 recirc elements and the one inside the case at the same time. Other than that, if your going to run 134, replace the expansion valve with a 134 valve. Dont sweat the oil, run ester100, add about 2 oz to the evap and 2 to the dryer.
Otherwise, its pretty straighup, just keep those fasteners organzied. :-)
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.