Head Gasket Set 996 1210 1212 990 Fits Case 1490 1394 1494 1390 1290 fits DavidOne New Aftermarket Replacement Head Gasket Set for David Brown and Fits Case Tractors This top gasket set seals the cylinder head on David Brown AD4 49, AD4 55, and AD4 55 T four cylinder diesel engines. The set includes all gaskets required to replace the cylinder head head gasket, valve cover, intake manifold, exhaust manifold, exhaust pipe, thermostat, combustion chamber, and injector seal but does not include valve seals. Bore diameter is 100.