Well, since it looks like the original poster had his questions answer I'm going to take over, lol. I'm trying to cost out doing this swap and figuring out everything that is needed to make this go smoothly (if anyone does this in the future). If I do go ahead with this swap I'll update with any additional things I run into. Here are two other threads discussion this: STI Block EJ20G heads?
and Ej20g + Ej257 = ?
My car has 550cc injectors, TD05-16g and using Apexi PFC for tune. I'm looking for around 350 hp atc. I imagine I'll be upgraded the MAF to a Z32 or Q45. If anyone can add to this list with numbers and any other parts needed I will update it with your posts to help make this an easy conversion for those in the future.
New parts needed
-Ej257 short block - 10103AB440
-Ej257 oil pump - 15010AA280
-Ej257 water pump - 21111AA240
-EJ257 timing belt - 13028AA240 if switching to new style tensioner
-EJ257 tensioner, mounting plate and extra idler -
I've also read that you can use the old style tensioner
but not sure which belt you'd use then?
-Head gasket -
if early legacy heads use EJ257 - 11044AA641
if wrx heads use EJ25D - 11044AA610
-Gasket kit - not sure whats all included - intake mani, exh,?
Also I would change (part numbers needed, not sure in differences between wrx and legacy heads here)
-EJ20g cam seals - 806732150
-Ej20g Valve Cover seals - are these needed or can they be cleaned and work like new?