Let me preface this by saying that I have installed Cusco engine and transmission mounts in place of the stock Subaru mounts.

According to the rules for engine mounts:
H. Engine mounts may be replaced, but must attach in the factory location(s) without additional modification or changes. Engine position may not be changed. The volume of metal in a replacement mount may not be increased relative to the volume of metal found in a stock mount for the particular application. Solid metal mounts are specifically prohibited. Any non-metallic inserts may be used.

Then the rules for transmission mounts:
E. Transmission mounts may be replaced, but must attach in the factory location(s) without additional modification or changes. Transmission position may not be changed. The amount of metal in a replacement mount may not be increased relative to the amount of metal found in a standard mount for the particular application. Solid metal mounts are specifically prohibited.

Anyone have an idea of whether the Cusco mounts are STS legal?

iirc...you may use the STi mounts but not the Cusco mounts because of the relationship between Subaru and STi. There was (or maybe still is) wording that specifically allowed upgraded mounts made and sold by factory performance divisions.

The Cuscos definately have more metal or less rubber compared to stock mounts. Clearly illegal. Sorry for the bad news, since they do offer a more solid connection.

Jay Storm

That's okay, locally I doubt anyone will care, I was just curious.

Thanks for the response.

Philip