And also I'd say a better videocard aswell, to add to your list of potential improvements. I'd look into the AMD RX cards (RX 480, 470,) or the Nvidia GTX 1060, just to give a starting point in looking.
There is not many people yet to give their results, hopefully there will be more, but some which may or may not be useful to your BeamNG use https://www.beamng.com/threads/your-performance-testing-results.37866/ Ram speed is important, not only amount of RAM, 8GB minimum I would say and at least 2666Mhz with modern CPUs running BeamNG, but of course depending from the budget. Also with limited budget it is worthwhile to look if there is used components or computers which you could get bit older, but still as well performing parts for same price, for example i7 2600K overclocked is still as good as any new one, worth to check if pricing of that used is within budget limitations. Old i5 models might be lot more bang for the buck again. I have seen RX 470 being sold bit over 100$ at Amazon, so worth shopping around.
Don't get this crappy HDD (Western Digital Blue 1TB 3.5" 5400RPM Internal Hard Drive) #1 It's slow, even for HDD standarts. #2 It's 2017, get SSD for system/games, leave HDD for storage (movies etc)
Yes it will on normal settings but change the ram to 6GB or 8GB Or higher for better experience as it eats it.
Memory and hard drive are both crap. Assuming your budget is the $600 range, I would try this: https://pcpartpicker.com/list/ZpysBP I understand that that doesn't include an operating system. But you are really shooting yourself in the foot with that non K 6600, hard drive, and RAM. Best of luck with your build.
I must question the K series CPU, do you really need to overclock? I have a i5 4430S and RX470 with 2X4GB DDR3 RAM modules and it feels quite well balanced. I would recommend 1X8GB of DDR4 (better for upgrade-ability) and a 7200RPM HDD (5400RPM ones are like an infection to me). Also spending a little less on the CPU and more on the GPU wouldn't hurt, but stick to quad (or higher) core CPU's as they're generally better for gaming than a fake quad core (HT i3). And one more thing to mention is that you'll need some decent fans to keep it cool (the case may include some basic ones).
