Is this a standard M42 throttle body?

[cheesebox]

This is the throttle body on my 318is:



I noticed the alloy part "A" on this one looks newer than the rest of it, and also there's hardly any thread exposed on the studs which nuts "B" are screwed on to.

Not having seen another, I can't tell if this one is standard or not. I was considering fitting a BBTB - no point if someone's done it...

[Jimbob]

You're gonna have to take it off mate, take a photo of the inside for us, can't really tell otherwise.

[tim_s]

The part "A" is the water jacket. they all have this (and one underneath the t/b). its no reason to assume its got a big bore tb because of this.
It looks factory to me, but a big bore one would look the same externally. i'm with jimbob - take it out then you'll tell! And personally I would ditch the water jacket.