The Pro Series Round, A-Frame Jack # PSRV20000103 will definitely definitely fit in frame as the 3" triangular bolt pattern is a standard, but I cannot 100% say that your existing wheel will fit. It most likely will, but I do have an option that I can 100% say will work.
The etrailer.com Round A-Frame Trailer Jack # TJA-5000T-B is a RAM jack, though this will be a little more heavy duty than your original one. It will have a 5,000 pound support capacity, a 3,000 pound lifting limit, and... view full answer...