what year ranger? mine was for a '96...so maybe they improved things since.
the arms may be correct, just compared to my old ford 600, it doesn't give as much height. this could also be partially due to a little less ground clearance of the R4 tires. at least i think R1's at 12.4-24 (the ford has 12.4-28) would be taller than R4's at 15.00-19.50.