Chattering going into 1st/Reverse

[Shizap]

Hey Guys,
I just got my car back on the road after working on it for the past few months. I replaced the clutch, clutch fork, clutch fork stud, pilot bushing, throwout bearing, and had the aftermarket spec flywheel resurfaced. However, the car is still chattering/vibrating pretty hard going into first and reverse. It works flawlessly once underway. I don't think its the brakes sticking because it easily rolls down the hill with the clutch in or when in neutral. Would love to hear some input on what you guys think the issue might be. Right now my guess is the flywheel is warped and the resurfacing didn't help the problem.
Thanks,
Scott

Update: Called Spec and they said that it is normal for the first 500 miles until everything gets seated right. I'll keep driving it and see how it goes.