Sniiiiik

With a bios update that board supports a i7 3770k

Intel Burn Test http://www.majorgeeks.com/files/details/intelburntest.html

OCCT is also good at finding errors.

Yeah, probably better of saving the money, it works good enough for csgo and some other games. Just bulit the rig a couple of weeks ago, happy with the way it performs but i ran into a sizable cpu bottleneck when playing BeamNG.Drive

Yeah, I doubt a CPU overclocked by a few hundred more megahertz will prove better for Beam.NG, to be honest.
 
Best bet is to save up some money and work on getting a new build later down the road!

I am able to get a q6600 localy, if i went for the q9450 i would need to buy it from ebay or someting and with the shipping costs it would not be worth it.

I'd personally choose the Q9300 over the Q6600 as it runs cooler.
 
If you feel like the extra overclocking on the Q6600 is worth it then you need to also consider whether it's worth the price.
 
Heck, you could even put money towards a new build in the future if you're patient enough.

Whilst the Q6600 may overclock a little further, the Q9300 would have some advantages which the other doesn't have and it runs cooler.
 
Why not get the Q9450; that'd be better, surely? You can utilise 12MB of L2 cache that way.
 
It'd be about 10% quicker if you got the Q9450.