EJ22T from a 91-94 Legacy T or the EJ20 from a 96-99 STi Type R Spec C ... both are pretty damn awesome..

EJ22T is the strongest block subaru built..it was used in the famed 22B and will run 30 psi and spin 8K + from the factory all day long.

Neither has had much fame here in the us.. but the rest of the world.. expesically in asia recognises them as some of the best engines aorund.

WRX/Sti didnt with car of the decade in the 90's for no reason.