I don't want to suggest you discard your air system, but from the dozens of threads I've read here on RCU on the FEJ F-16 gear....it really looks like converting them to electric is the consencus.
I have seen these retracts and most folks don't realize how massive they are, and how much air it takes to cycle them.

Whatever you do, if you dont feel happy or think you can trust the system not to have leaks, DONT FLY IT! I have repaired F-16s from belly landings more than I care for, so trust me avoid it at all cost.

Good luck!

David