slide carbs are for buggies and monster trucks. I ordered a OS with a slide and the fella at the hobby shop said it wouldnt work, that I needed the rotary type.
Rotary carbs offer a larger response in the middle of the power
band. This works well for off-road applications when throttle
response must be varied.
Slide Valve carbs provide greater response at the beginning and end
of the power band. This works well for on-road and racing
applications for fast take-offs and high speed.
Many high-performance engines have short lives, as racers constantly
strive to "lean them out" for greater performance. Unfortunately,
it also makes engines run hotter, which reduces their lives.