This is not true but not far from the truth. If you use blocks that are smaller displacement with large displacement heads you run the risk of valve interference. But most people use large displacement blocks with smaller or equal heads.subaru engines are like legos man. lol. any head will fit on any block. take a 1.8 and put it on a 2.5 and it will work. the only difference is wiring, and compression. same with all the blocks fitting the trannys. for the exception of the ej22t or k. those have different bolt patterns. but you dont want them anyway.
yes it will work but the compression will be lower and power will be down a bit. all the timing gears will work, may have to use the old sytle tensioner if the 97 block has that type.I am in a similar situation but I have a SOHC 00 RS that decided to toast the main bearing. Is it possible to use a EJ25D block out of a 97 DOHC Legacy?
I have connections to a good block but want to know if I can swap over my timing belt and tensioners onto that block. Anyone know?
yes it will work but the compression will be lower and power will be down a bit. All the timing gears will work, may have to use the old sytle tensioner if the 97 block has that type.
make damn sure you use the thick mls gaskets when you do this. Phase i 2.5 pistons go above the deck surface at tdc - i just did this exzct swap and made the mistake of using the thin sti gaskets and the pistons where tapping the heads - seemed fine turning it over by hand but made awful noises when running.