Well I was able to confirm that the tranny in my stang is indeed a 99 world class T5 from a V6. The internals looked fine except the synchro for 4th de bonded (The little friction like sandpaper inside the ring) and thus the reason for the 4th gear grind. Got a new synchro for free so that problem is done. Next up is the output shaft. Since its a 99, it has no hole for the clip that holds the speedo gear in place. This weekend I will be drilling the hole in the output shaft and I already picked up the clip for $2. Should be a fairly easy repair that will get me back on the road for now. Eventually when this T5 genades, I will upgrade to something else that can handle more power.