ETH is the DC order code for the H. O. engine. Your transmission order code is DEE. DD's are Diesel Dynamics injecters, Stage I, II or III. EZ's and PE's are plug in boxes that alter the output from factory ECM to the injection pump to improve performance.
Do a search on some of the early 24 valve posts, lots of good info there.
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ex Ford tech, now driving '01. 5 2500 4X4 QC LB ETH/DEE SLT 3. 54, Patriot Blue