did you replace the clutch as well, or only the spacers and spring? I noticed my slipping when I try to accelerate to quickly.Mine was slipping last May. I used the springs from the 1500 and the spacers from Gadgets web site. I did the install myself and it was pretty simple.
As I talked with the person who manufactures the spacers, his opinion was this set up was just as good, if not better, than using the gorilla.
The pull on the lever is reasonable and I do not notice any difficulty in stress in stop and go traffic at all.
you will need an impact wrench to do this project, but I think I got mine for under 15 dollars new.