It could be confusing (if not incorrect) to refer to a 235's fan blade as if one size of blade was used on all years of 235s (41-63). And, it is not correct to state that only one size/style of fan blade was used on all years of 216s (37-53).
Car vs truck 235 fan blade might be different in different years. And, several sizes of blades (and number/configuration of blades) were used on car and truck 216 engines.
Seven different blades were used on 216 AND 235 engines from 37-53. The very common 16.75" blade was a length only used on 1953 and earlier engines (216 and 235). However, an 18" blade used on both low pressure engines and on high-pressure 54/55 235 engines.
It looks like 17" or 20" blades were used on various (high-pressure) 235 engines (car and truck) from 55-2nd through 1957 (and maybe through 1963?).
