The only way I can duplicate that behavior for 1065 is if the character value actually has 5 leading blanks in the value:
data example;
x1='1065';
x2=' 1065';
x3=' 1065';
x4=' 1065';
x5=' 1065';
x6=' 1065';
y1= input(x1,8.);
y2= input(x2,8.);
y3= input(x3,8.);
y4= input(x4,8.);
y5= input(x5,8.);
y6= input(x6,8.);
run;
If your character data is inconsistent then use the LEFT instruction to remove the leading spaces with the input:
data example;
x6=' 1065';
y6= input(left(x6),8.);
run;
the 32. informat will work 1065 until you have 29 leading spaces. 29 spaces plus 4 numeric positions = 33 characters to read and 32. informat will only use the first 32.
This is an example of "Know thy data".