EJ25 head gasket on EJ20
 

I have an EJ20G engine which will be rebuilt in the near future. While looking at prices of head gaskets I noticed that the Ebay price of OEM 2.5l head gaskets is about 1/3 the cost of Cometic 2.0l head gaskets. That got me thinking, is it possible to use the 2.5 head gaskets on a 2.0? Looking at an EJ20 block I've got lying around, it looks like the EJ25 gasket should still be able to seal (there is only 7mm difference between the EJ20 and EJ25 bore).

Has anyone ever tried it or does anyone know of any reason why it might not work?

Dont do it. Bad move. Use correct gaskets.

Thanks for the response Bassman, but what is the reason why the 2.5 headgasket would not work?

They wont seal properly. The 7mm difference is massive. That should tell you something. Different size headgaskets.