Hello...

Ive been told that slapping a V7 STI bugeye block ( or Subaru EJ207 shortblock) onto my V5 heads will deliver a Compression ratio of 9:1

Lot of confusion here as Subaru claims One thing and in reality does another..

This is what I've found ( according to msr)

99-00 wrx is 8.5:1, claim 8:1,
99-00 sti is a true 8:1,
02 sti short is 8.3:1,
wrx RA 99-00 claim, 9:1, true 8.5:1 (uses same pistons as 8:1 wrx


And....

pistons in these V 7sti shortblocks have a 6cc dish, and are approx 1.5mm down from the top of the block..

v5 heads. 51cc volume..

Can anyone confirm these figures ?.

So if I just bolt my heads onto a V7 STI block and use thinner gaskets. From .8 to .6 what will be the resultant compression ratio..

Have been using a CR calculator but no luck..

Any help appreciated...