Well I've got another engine (secondhand replacement in the end but it has only done about 50k miles) and am currently stripping it down to a longblock for a clean up ready to take my modified intake manifold and other bits.
Looking over the engine block it seemed remarkably similar to my RA closed deck block and after a quick search it seems some very early WRXs came with them too! Looks like I lucked out on this engine! I'll be able to confirm tomorrow when I've taken the rear cambelt covers off to check for some typical hatching marks above the oil/water heat exchanger...
Should be back on the road in a couple of weeks
