New owner of a used Mustang


Profile Violation
99-04 is all New Edge. Everything will work between years, some with
modifications. Late model '04s got the 3.9 V6, but it will still run in
99-03. However, the new Edge basic proportions, interior design, and
chassis remained the same as the previous model.

A split port induction system was added in 1999 for 190HP

1999–2000, while the Mustang GT's 4.6 L V8 saw an increase in output to 260HP
due to a new head design.

01-04's V6 HP was increased to 193 HP.

The 3.9, on top of the 01-04 increases, is another +3 ft-lbs in torque, with
Noise, Vibration & Harmonics improvements.

Pete fender

Pete Fender
The only major parts that differ are the pistons and engine bore, they made some changes and refactored 3.8 to 3.9, but all other parts interchange.
It's a worthwhile project as these cars are getting scarce.