I have a 4770k and previously I've done 4.5 at 1.2v and it just blue screens and fails. Any help? I've looked at a lot of tutorials and followed them in detail. BTW I have a Sabertooth Z87.
There is no guarantee that any chip will ever be stable at any given overclock nor that it will remain stable at a given overclock for any length of time.
If extra cooling and a little extra voltage cannot stabilize your CPU, your next best option is to dial it back to 4.4GHz or lower.
when overclocking blue screen crashes generally are a ram or temp issue; so you might want to look at downclocking your ram and see if that helps (or overclock it or boost it's voltage or something)
that said, cpus are like a lottery, some overclock well, some dont. for haswell cpus generally 4.3ghz seems to be the average achievable overclock.