What ever you do dont run the 2.5 block with the EJ205 heads. Its really not a good combo. I tune them all the time. They are knock happy and just not a good sounding motor.
Dan, If you put the 2.5 block in make Damn sure you get some thick head gaskets. If you dont you will end up with Compression of 9.2-9.5 to 1 and its a BEAR to make any power on pump 91.... Get custom pistons in the 8 to 1 range or at a min get the thicker Gaskets.