From the fiche there are two different rod assemblies used in the 83 VF750. You should have two of each type in your engine, so looks like between the two of them you will have enough rods to fix your existing motor. http://cheapcycleparts.com/model_years/230-honda-1983-750-interceptor-VF750F/assemblies/4420
in going back thru gen 1 posts it appears jamie daugherty has much time inside these gen 1 engines. PLEASE discuss what you know about the crank rod bearing failures on the 83 vf750f and also about the overhead. Coleross has a parts bike, but it has exactly the same problem. I think he needs to investigate what others have found about this problem on this bike, & jamie daugherty may be the old faithful geyser of vf750f helpfull info. Since he has already been on this thread, this message should reach him.