Exhaust Manifold 70225323 Fits Allis Chalmers BOne New Aftermarket Replacement Intake and Exhaust Manifold Fits Allis Chalmers Tractors This combined intake and exhaust manifold is a direct aftermarket replacement Fits Allis Chalmers (AC) compact and utility tractors equipped with the 125 cubic inch 4 cylinder gasoline engine. The manifold serves dual duty handling both the intake air fuel charge and exhaust gas flow from a single cast housing, a common design on these classic tractor engines.