yea, im pretty sure that it is the tranny mount. it gives a sound that initially i thought the gears in the differential would slip, but i have no problem accelerating even at full throttle. i occasionally grind into gear, even if the clutch is in, and sometimes it is really hard to get into gear.
a buddy of mine had the same problem and suggested tranny mount, so we jacked it up. sure enough, the tranny mount was torn up. i have a new one at my house, it took ford 2 days to get me a new one, but i posted to see if anyone had the same problem or had upgraded to an aftermarket.