Guy I need help fast........... I am busy stripping the left front fork. I have a 1981 GL 1100 Interstate but when I took the springs out there are two, 1 x short sping and 1 x long spring with a length of 465mm (18.3in) my question is how much fork oil do I put in, do I use the spec for the 1981 model which is 8oz or do I use the 1983 model spec with is 9oz. The info I have states that the unit with two springs with a long spring length of 18.2in is in fact a 1983 model. My bike has the single piston bake calipers and does not have the antidive device in the front shocks..... So how much oil do I use and if I over fill what is the result....