lewis,
the blocks for all GD impreza 2litre EJ207's are identicle, (semi closed deck etc)
the only thing you need to look out for is on the top of the block (under the manifold/alternator) they stamp the piston grade in a pattern like this

A|A
A|A

or

B|A
B|A

with varying combinations of A,B,C,D

i have a chart somewhere which tells you what each combination means, though i'll need to look around for it.

basically this determines it to be either a WRX, STI, SPEC-C, S20X motor

__________________

Long live the WRC

aussie still got forged pistons for 02-05sti 2.0ltr variants

Subaru marketing called the hypereutectic pistons in the Aus 03-05 STi "Forged" Agreed they are in fact not a true forged piston like the 02STi. Hence the Aus 02 STi short motor is the most desirable along with its semi closed deck. Would be interesting to know what the piston codes are.

BTW John Keating (Spare Parts Manager) at Regents in Osb Park 9273 2050 has 4x Brand New V7 STi Short Motors awaiting good homes...mention Perth WRX and you can take one home for $2500 plus GST. John is not sure if these are true forged or hypers....so what hope do we have

another thing to note is that in most cases, the forged pistons from an sti would not be as strong as aftermarket variants (JUN, CP etc). i'd go for a built motor over a stock sti any day.