You should check with K&N (or your engine builder) to find out what the requirements are for air flow on that size motor. I believe that it is (96 sq. in) for a big block. Height x circumference will give you the sq in. On a 3 x 10"dia flame arrestor, 3 x(10 x (3.1416)) = 94.25 sq in. I know some people say that it doen't matter. But I thought mine ran better with the taller cleaner. Just something that you may want to look into.