will a H100i in Push/Pull fit in a corsair carbide 300r?
yeah! but you will mount the two fans outside on the top of the case if you have a tall ram, if not then they probably fit
Yeah it would probably fit, but i still wouldnt recommend it. I have tried it my self and it only performs 3 or 4 degrees better and for me personaly it isnt worth the extra noise. However if you gonna undervolt the fans, then it could be a good idea.