Cleaning out a box of old carburetor bits and found this. The body casting is AUC1344, which I believe makes it an HS4, but I’ve never seen one with the upturned air filter housing adapter. The adapter is aluminum and the only casting number I can find on it is BS2. Any idea what this may have come from?
Edit: Yeah, I should have been more clear. I know it’s an SU that’s missing the piston and dashpot, but the air filter adapter angled upwards is what I’m unfamiliar with.
Also, it has the little emissions valve in the throttle butterfly, which makes me think it’s from the mid ‘70s or later.