If it is for twins a T4 is good. Single you need a T6 and at least a 88mm probably better off with a 91... What are you looking to make for HP. Boost means nothing those W9 heads will flow alot.

11.67@118 1.88 60' with only 7-8 lbs of boost. Turbocharged, megasquirted, 407 BB, 440 source heads, roller cam, 9:1 comp. http://s292.photobucket.com/albums/mm14/beansgracie