Sn1992-1361850 :
yes its right that u can o.c. on z series board
a z75,z77,z68
b75 are bussines series b boards
WRONG.
http://www.msi.com/product/mb/B75MA-P45.html#/?div=Overview
There's even an Overclock Genie in software that can handle overclocking for you.
Tip on overclocking the i5-3570K:
You might be able to overclock to 4.2GHz (Turbo) without making other changes related to overclocking thus keeping all the Power Savings features intact. If so, I recommend you stick with that as it will reduce the heat and noise a fair amount. I stress-tested in Prime95 and got 68degC at 4.2GHz on my i7-3770K but at 4.4GHz I had to follow an overclocking guide and make a lot of changes before it was stable then I was at 88degC. Obviously a worst-case scenario but since overclocking generally doesn't make too much difference in games I find this is the ideal balance (my room gets very hot quickly as well).
Other:
*Next time, try going to the motherboards web page first. The answer is right there...