can anyone tell me what sets the apart form other sti heads VISUALLY. i know the cams are more agressive ect.. are the valves larger or ports? thanks alot

 

Offset Inlet Manifold bolt holes ( denoting 1999 onwards)
Large Inlet Ports (compared to 2001> WRX)
Underbucket Shims

 

offset how? gota pic?

what are underbucket shims

 

Offset - as in all 4 Inlet manifold bolt holes aren't in a straight line.

Underbucket Shims - As in the valve shim sits under the bucket, on top of the spring retainer. (WRX/UK Turbo from 1997> have the shim sat on top of the bucket)

 

gotcha,excellent. are they the only heads to have underbucket shims then.

anything else? cams ect..

 

No, STi3 and 4 have underbucket shims, but don't have the offset inlet manifold bolt holes IYSWIM

 

Sti3,4,5 and 6 cams have different durations, overlap and lift to their UK/WRX equivalent.

All V1 to 4 cams have slots in the end for the pulley to locate.
V5+6 have pins in the end for the pulley to locate.