DiD it on 3-4 shift @ 5500rpm, BANG!!!! no power shifting either. I installed a SPEC3+ 700 miles ago. I recommend a shaft up grade is your putting a aggressive clutch in. You can get a 26spline @ Promotion with deposite 300-400$ and a 1-2month waiting list. Or do what i did and call CR @ TillmanSpeed and get a treated stock 10spline. Heat or Kryo treated for 250ish$. Just food for thought.