Joe...I dont think the slide is backwards. I actually got everything back together by the end of the night.
I just screwed the c-clip all the way down to the bottom. Im not sure where I had it before. Where is a good place to start it off at?
When you say you screwed the C clip all the way to the bottom, do you mean you clipped it on the lowest notch on the needle?
It should start at the second from the top, then adjust if needed from there.
That slide has to sit all the way down in there, or you are going to start your engine and it's going to want to rev to the moon.
In your photo, the cable end looks like it's sticking out of the bottom of the slide, and that's not right. You order should be spring over the cable, then put your needle with the C clip in the slide, drop the pac-man washer over it and while holding the spring compressed hook the cable end in the recess at the bottom of the slide. The spring holds the big pac-man washer that holds the C clip and needle inside the slide....The spring pressure will then hold the whole works together and you can slide it in.
Once everything is properly set, the cable outer sheath should have little (1/32") freeplay at the end, unless you got a whacked cable outer that is way too short....that still wouldn't explain why the slide is not all the way down in.
Did that help?