well, i will answer myself....
The NTE3027 aka ECG3027 can be used with free-track and they work nicely, at least for me. Just be aware that apparently there are two version of these IR Led, one old version wich only have +/-22° of angle and an upgraded version with +/-45°... i think i got the old version cause the specs that came printed on the envelope of my IR leds (Fv 1.5v -- Fi 100mA), the upgraded version is rated 1.3v at 150mA.
Anyway my free-track setup is working very nice, i think i can tune it more to get it working even better.... by the way i found that in my case using RGB instead of i420 give me better IR Led isolation cause the led pattern is less blurry...
Regards