I think all of the VTX1300C engines (2010+) are common with the Fury, whereas the VTX1800 is not. The VTX1300 engine (pre 2010) is carbonated instead of fuel-injected, so the mount could be different (I don't know).
Yeah the older 1300 engine spike does not fit straight on. Some of our forum members have made their own modifications to make it fit. The other option is to use an adapter and get a HD spike, which is what I did.