??? What's so hard with replacing the fuek system on an IDI? 1. Undo 4 vibration dampeners 2. Pull 8 injector lines 3. Pull supply line. 4. Pull return caps. 5. Remove 8 injectors. If you have an impact with deep socket, this is easy. 6. Install new O-rings on injectors. 7. Install new injectors. 8. Install return caps. 9. Cut return hose to fit, clamp in place. 10. Remove front ip cover plate. 11. Remove 3 5/16 bolts. 12. Remove 3 9/16 nuts holding the IP in. 13. Slide old IP out 14. Install new IP dot to dot. 15. Reinstall 3 nuts, then 3 bolts. 16. Install front cover with 1-minute-gasket 17. Install 8 injector lines, fuel supply line. Leave loose at injector side. 18. Install vibration dampeners. 19. Floor throttle, crank to prime. 20. Tighten 8 injector lines. 21. Warm truck up, see how timing is, adjust accordingly. Done! I Think 3 hours is a reasonable estimate if you have your new parts all ready and available.