I agree with Rice. I just put on my TWM ss about 2 weeks ago. I used lithium grease as well. After my install, I was pulling my car out of the garage, and I noticed how fucking stiff it was too. The first thing I thought was "I just got really fucking ripped off." I planned on putting my stock shifter back on that week when I had a day off. SO, I had to drive with the ss for like 4 days till I could put my stock one back on. BUT, by the time the 4th day got there, my TWM had eased up and broken in. I was in love with it!! There is no way in hell I'm going back to that piece of shit stock shifter now. Give it time to break in and you will love it. It's so crisp and precise.
I also agree about your spring adjustment. Drive around for about 2 weeks and give your clutch time to "break in." If you still have the exact same problem, take in it for a spring adjustment. But I think driving it for a couple of weeks will fix the problem. Good choice on clutch and ss. I think ACT makes the TRD