Performance Upgrades

I have a 95 Lesabre with the 3800 model L engine. Are there some simple performance upgrades that are relatively cheap? I was thinking on the order of air cleaner, exhaust, compupter and possibly heads. Any opinions and ideas on biggest bang for the buck?
Thanks!

You won't be finding anything too cheap for the 3800. I believe headers along will cost up to $600. K+N Air filter is probably the cheapest upgrade you will find. Catylitic converters significantly decrease exhaust flow. If you are able to weld, you can likely fit a dual outlet muffler with a single inlet on your car, increasing flow. They do make chips for the computer, but I don't know what those will run for as far as their price.