I have two 235 motors, one a '55 and one a '56. Of course the Intake Manifolds on each of them are identical. I recently acquired an NOS manifold (which I believe is from a newer year) in which the heat riser "box" is shorter, than the ones on the '55 & '56. I was told that the NOS manifold may not work with the carb I have as with a shorter "box" the gases are not heated enough and I believe I was told the carb would run rich. Is anyone familiar with this problem, or had similar experiences with the newer type of manifold? (NOTE: The NOS manifold is DEFINATELY 235-it was attached to an NOS exhaust manifold that is exactly like the ones I have).