with a cai and exhaust you wont need a tune. not until you get into big stuff like an HCI. i have a 95 5.0 and im doing a gt40p heads (ported, polished, and big valves), gt40 intake, and a trickflow stage 1 cam. with headers, bigger throttlebody, cai, and mac exhaust. the gt40 heads you can pick up at a local pull apart for a decent price along with that intake, after that you can spend as much or as little on them as you want. im spending a good bit but im still coming up
400-500 dollars cheaper than aluminum heads which for a good set will be over grand, i have about
600-700 dollars in mine. and they will flow damn near as good as a low end aluminum head. so they are great for power and a budget build. some people say they take a special header but you can get around that with 90* sparkplug boots. i picked up my heads and intake at my pull apart for around 160 for all of it. of course if you want better heads you can look on other forums or here for people selling aluminums for around
600-700 dollars. me i didnt have the cash on had so i spaced it out over time and was easier on the wallet. you can also find headers almost anywhere. i bought some ford racing short $60 shipped. just dig around and have fun man. dont hesitate to send pms and ask questions. there are alot of 4.6 guys on here but us 5.0 are still pokin around.