Review on 🔧 Enhanced Mr. Gasket 1933MRG Carburetor Adapter Kit - Converts 2Bbl to 4Bbl Effortlessly by Carlos King

uses this to install a 4 cylinder crankcase on an old AMC 343 2 cylinder. I see other browsers had installation and sharing issues, but there are a few other configurations. You will likely need to remove the pins and replace them with the hardware that comes with them. Some headers like mine had an intermediate plate that had to be removed. but otherwise all seals and accessories were included and fit perfectly. Screw the adapter to the manifold, then the carburetor to the adapter. I can't speak to the opposite (4 barrels to 2 barrels) but I believe it's machined to then use the same socket head screws instead of studs (you need to attach the carb to the adapter and then the adapter screw to the manifold right in such an order).