Hello everyone,

What are the main differences between STi 1-4 heads?

I've currently got 1 wrx head (hydaulid lifters) and 1 RA head (manual lifters) on my94 RA , apparently thats no good and I need new ones, so I've spotted some STi ones for sale and was wondering what was the difference between all the variants.

Whats the best etc and how much will I benifit from more recent ones etc..

Thanks

 

your set up will only allow upto version 4 heads due to the inlet manifold and cam wheel pick up etc..

the best of that bunch is STi3, followed by STi4, followed by Sti 1 or 2 solid lifters.. just make sure you check the sti4 heads are really sti4.. ie. they are under bucket shimmed etc..

Simon