This auction is for a pair of downdraft intake manifolds for the Oldsmobile/Buick/Rover aluminum V8 engines built by GM in the early 1960's and then by Rover till much later. The four carburetors included are cast with the Weber trademark and are 44IDF81. I am listing this manifold for a friend who has passed away and his family has asked me to sell the manifold for them, so I do not have first hand knowledge of the origin story.
Please note that due to the cylinder bore spacing of these engines the carbs are placed close together. The throttle shafts have to be shortened so that they fit together on the manifolds as shown in the photos. Note that a mistake was made on one of the carbs and the wrong end of the throttle shaft was shortened. Therefore there are not enough threads on the throttle shaft to hold the idle speed lever properly. My solution would be a new throttle shaft. I have a reproduction Weber manifold on another auction. This was ordered by my friend to use in place of the miss shortened carb.
The rectangular ports measure about 1 3/4 by 1 1/8 and the round ports are slightly larger than the 44mm bore of the carbs.
Note that the thermostat housing is included in the auction.