Hi Kweassa,
according to Manfred Griehl, the Me 109G-14 closed a small gap, the first G-14 examples being delivered in June 1944, and the first G-10 and K-14 being delivered around October 1944.
Since the first G-10 examples were delivered with DB605AS, too, as the DB605D wasn't available in sufficient numbers yet, I think the gap-closing G-14 would be the G-14/AS anyway.
It's my impression that the G-10 and G-14 should have very similar performance when equipped with the same engine model, anyway. A difference could result if the G-14 were not equipped with MW50: According to Griehl, MW50 was standard for the DB605DC-equipped G-10.
I think Vermillion's suggestion of an MW50-eqipped Me 109G-6 would close a larger gap, though :-)
Regards,
Henning (HoHun)