Selling 1965 used Buick V8 matching motor and transmission. Bought it from guy who advertised it as Wildcat 401 Nailhead (clearly not true) with fewer than 40k miles (probably close to mileage). Cast iron 4-Barrel carburetor intake indicates possibly the larger 340 ci engine but I did not research block serial number AB 81357943. Would like to sell engine and matching 400 2 speed transmission together. Motor is located in Baton Rouge, Louisiana and buyer pays freight or picks up locally. Email for additional pictures. The valve covers removed show a very clean and well stored motor for all these years. Turns freely and believe it does not require any rebuilding to run strong. That is only my speculation!