STI or WRX head, how do you tell?
 

I have an engine that I am looking to rebuild, I think it came out of a legacy GTB. What heads should it have on it and how do i tell the difference.

I don't know what year of engine you are looking at but on the STi the shims are under a bucket whereas on the WRX the shiims are on top.

The shims are on top of the buckets so I guess they are WRX heads. I think it is a 2000 engine. What advantage do you get by having the shims under the buckets??

higher rev limit.. also the sti heads have high lift and longer duration cams.

Simon