I have an Oliver indusial tractor 77 or 88? I have searched for a serial # but cannot find anything. It needs new manifolds before it catches on fire. On the back side of the intake manifold there are two numbers: 624N and 142581. I was told that because the 88 engine is larger it had a bigger carburetor. On my tractor the inside throat of the carb is: 1.055 and the intake manifold is: .925 
Any help or sugestions would be great.
Thanks
Rich Briscoe