The engine build date is on a tag on the passenger side near cylinder 1 & 2. It's 3 digits, 2 letters, and 2 digits. The first digit is the year, second & third digit is the month, 2 letters should by MX for the 4.0L then last 2 digits are the day.
Mine is 501MX19 so Jan, 19 2005 for me. Yup E05 applies to mine and my OPDA went and took the cam with it.
2005 Wrangler Sport, 4.0L, 6spd
2" BB, JKS 1.25" BL & MML, M/T MTZ 33x12.50R15
HP D30: Aussie Locker, D44: Eaton Elocker