most if not all v2 parts will be drop in. CA gearboxes are a bit strange though, a few parts can be off spec. If you upgrade the guts, you should measure the exact length of the nozzle, some brands use slightly different lengths, this also makes it worse as the hop-up castings are all different so the hop up and nozzle are usually a matched pair, but the front of the gearbox is also an issue as it can sit a tiny bit farther forward or backwards from brand to brand. This causes headaches with feeding or air sealing.
Always take the part from your gun and measure before ordering an upgrade part. But yes, the length of your barrel should be 509.
I futz with V2s, V3s and V6s. I could be wrong... but probably, most likely not, as far as I know.