I have a Gold Cup that turns over 13,800 with an APC 11-7, 15% nitro and K&B 1L plug with a Semco Muffler. Chose the plug cause its black but it works good. I think the Gold Cup has a larger carb than the Silverline. The throat diameter is the same or slightly smaller, but there is no spray bar to restrict flow. I have not flown it yet, but someday.