That's a rare sight! Glad it's a clean one. I know a lot of people like how the GTS upper intake manifold drives better than the GT manifold. There's a lot of information here about the swap, as well as it's pros and cons. Mild tuning is also fairly simple these days and worth looking into for getting the most out of the stock engine. And finally if you're more adventurous there's a couple different V6 engines with more displacement and power that swap in, one a lot easier than the other.