Use the center brace from the Evo IV MS. #49356
Something I saw Charlie S. from Novak did on his EVO 3 a couple of years ago was he removed the stock center brace and doubled up the top carbon fiber deck (he also counter sunk the top deck of the 2). He said it was stiff enough and it did not ad as much weight as the plastic center brace.
thanks for the good tips guys.. Its definatly worth a shot