Alternator upgrade

The engine performance takes a big hit when A/C is on. Will swap in a more powerful alternator help?

No! The power loss if due to the compressor being engaged. It usually takes 15 hp to drive the compressor so that is why you lose so much power. The compressor is driven by the engine and it takes power to turn it. If you want to increase power you may want to try a compressor cutoff as they should still be available.

I put in a K&N air filter in my '95 wagon and made a HUGE difference with the AC on.