So just an update to those who are still interested - had quite a few clumsy moments as someone who rarely touches the internals of his computer.
This is what the system was like on the inside - still with the i5-4430, tracking temps via Speccy back then (switched only to HWINFO64 after some users told me it was better), it would regularly thermal throttle.
Apologize for the case/dust gore.
Cleaned it up actually, and ran water through the heat sink to get out all of the clogged dust bunnies. I didn't reapply thermal paste after cleaning out the fan, as I didn't have any, and my Cryorig H7 was arriving the next day regardless. Oh yeah, I also broke one of the corner mounting pins (the white clip portion that pokes through the motherboard).
Despite the non-re-application, and being mounted only on 3 pins, the stock fan still did well and had it idling in the 30s, but funny enough for that one night of using the CPU, it would regularly thermal throttle, and I had to physically reach into my case (I left the side panel off since I knew I was going to work on it tomorrow anyways), and lightly press the fan down where the blue sticker is to make better contact with the CPU heatsink. I could actually see in real time the temperature go from 90s to 70s, which maybe some of you might think is barbaric, but I found the experience pretty amusing.
Anyways, my heatsink arrived this morning along with the CPU. After installing it, I found the size disparity pretty amusing.
And then re-added my GPU. Apparently if you have a mountain on top of a tiny plains, adding a second mountain doesn't make the first one blend in better.
Anyways, I got it back in the case now, I also didn't re-mount the hard drive bays (I was concerned about air ventilation on my first startup with the 4790k).
After a small panic and flipping through several manuals, I realized I reversed the reset case switch and the power switch connectors to the motherboard, and then she fired up. The entire cleaning process and fan installation took about 3 hours, unfortunately my motherboard is so damn tiny in this case, the designed exposed slot for motherboards in my case is waaay off center, so to attach the backplate of the Cryorig H7 I have to remove the entire motherboard out first. As you can see, my mobo doesn't even clear the gap.
However she boots up just fine, first time in my BIOS recognizing (I bought my board in 2015, so didn't need to update the BIOS for the Haswell Refresh, although it is only v6.6 [latest for my board is 2015 v6.7]) my mobo kept reading the CPU temperature in the high 30s - low 40s on idle.
After resetting and starting up HWInfo, the temperature comfortably reads in the mid 30s on idle. I haven't put it on load yet, but loading up my modded instance didn't even seem to push it past 60% of utilization.
Ingame, areas ofmy base where I used to struggle at around 5-10 fps is comfortable around 40-50. I can also alt+tab in and out of the game easier than before (important when I usually want to do scripting or testing for modpack development). Pretty happy with the results, and happy that it only really costed me about $240 to upgrade, hopefully this can carry me a couple more years. New mic and audio interface coming this weekend. Didn't originally mean to turn this into a blog post, but it's a small victory that I'm happy with.
edit: Does anyone have any single thread benchmark reports of the I5-4430 versus the i7-4790k? Or are benchmarks not as reliable? I'm happy with the frame improvement but I was wondering if I could find anything else that had a more technical report on it, there were some graphs on CPUbenchmark, but wasn't sure how reliable those were. The reason why is because I know the 4790k blows the 4430 out of the water in terms of multithreaded performance, but wasn't exactly sure how much better in single thread department.,
Also I have turbo boost off, don't think I need it, so figured might as well leave it off.