I would think it's okay as long as you mind the copyright issue. Also, ADB/Mongoose don't want anything statted-up for SFU ships that exist in another game but not yet in ACTA. You might want to be careful with posting so called obvious variants*; these are simple conversions of existing ships which ADB/ Mongoose may do themselves at some point in the future.
If you are coming up with your own stats for your own ship designs, then it should be fine.
*from the ADB auto-reject list: Obvious variants (leader, scout, carrier, PFT, commando, drone, minesweeper) of standard warships which do not already have them (e.g., Klingon F6, E5, Kzinti DW, Orion DW, Gorn BDD, Fed FFB, Gorn CM, etc.). You might suggest or ask for such a ship, but if we agree it is needed, it will be designed in-house.