For the overclock you want at the temps you want you're going to need a better cooler. The t4 is pretty low budget for a reason and doesn't cool as well as the 212 evo. The t4 couldn't keep an athlon x4 620 cooled when oc'd to 3.6ghz. The 212 evo kept it at 45c under stress, the t4 reached 72c and failed the test.
http://www.dvtests.com/cooler-master-hyper-t4-test-and-review/
To get that kind of cooling performance you'd be better off with something like the cryorig h7 which is still a lower budget cooler at around $35 but does a good job and keeps temps under control without interfering with the ram. At stock load on an i7 4770k it kept it around 52c and since the 4790k is clocked a bit higher and runs a bit warmer I think it will...