torx cylinder head bolt L6 250

Hello all.

I'm trying to remove the cylinder head on this engine. Unfortunately, there is one bolt on the very front, passenger side of the engine that has a torx head. Anybody know what size torx socket fits it? The largest torx socket I have is a T47 and it's not large enough. I'd prefer to buy just the one socket as I am not a professional mechanic and will probably never use this one again, let alone an entire set. By the way, the engine is already disassembled down to the cylinder head, so I can't drive it to an auto store and match a socket to the bolt. Thanks.

Brian