If you're going to change to the dual A/C aux. fans you'll need to change the following:
1) powersteering cooling pipe;
2) fan ballast-resistor;
3) radiator reinforcement strut;
If you're going to a R134a condenser (recommended if your're going to R134a refrigerant) then you'll need a new dryer/receiver; o-rings; R134a temp. switch, and A/C hose,
The 500E is different in that it has TWO radiator reinforcement struts, and mounts one of the horns down below.
Unless you have to go to R134a, I would stick with R12 BUT still do the dual-fans. That baby will blow ICE-COLD.
I did the dual-fan upgrade with R134a, new condenser, and new A/C pump, and I'm very happy.
I did the R134a conversion WITHOUT the dual-fans and R134a condenser and the cooling performance was for my black wagon POOR.
1988 360TE AMG