There are 3 types of manifold.
Type 1 is standard on an early 850/X70 Turbo,T5,T5/R and R and is average,
Type 2 (aka Japanifold) started somewhere toward the end of the P80 X70 I believe, not sure exactly when, it is the type that is fitted to P2 cars i believe. It is a big improvement and is often preferred over the Type 3 as it helps retain the signature 5 cylinder noise we all like.
Type 3 is the S60R/S70R manifold from around 04 on. It is the best performance wise but is only marginally better than the japanifold.