what's the different between traxxas 4146x and 4146? i want replace the clutch spring, but lhs only got 4146, is the spring on 4146 gonna work like 4146x?

btw, while my tsunami broken and waiting for replacment part, got this on the site, wow, it's fast. pinion gear setup is 19t and 23t, tsais nitro devil exhaust done by previous owner. and i got whole lot of extra parts with it, also 3 body, 5 set of rims, 4 set of tires, here're the pictures: