For none overclocking, the two have almost the same core performance although FX 4350 will be slightly better in games than use 1-4 cores. New BF4 and some new AA titles that use more than 4 cores would be better on FX 6300.
The FX 6300 is also a solid choice for enthusiasts, people who do a lot of streaming, rendering and video editing.
Also, I have no idea why you are looking at FX 4350. Athlon 860K would be a slightly better choice over the FX Quad Core.
860K would also be slightly better than FX 6300 in programs and games that use 1-4 cores. FX 6300 wins in multi tasking.
If you don't do rendering, editing and you don't play new titles, then Pentium G3258 which is a dual core will rip apart any of the AMD CPUs out there in...