nothing will solve the powerloss, an UDP is your best bet.
I actually dont notice the ac powerloss anymore since the UDP.

any load on the engine will cause a powerloss and the a/c system is a huge load.

the final drive mod will do nothing to fix that.
you might just have a faster car after and not care about the a/c loss.

1998 dodge avenger 4 cyl AT
Mods are:
Not enough