I have the new rog helios case, it says it will fit a 420 rad in front but I cant find a rad that will fit the space so I'm thinking of putting 360 in instead but my question is will 30mm 360 up top and a 54mm 360 in front work with 2 evga 2080tis one is a ftw3 ultra the other is a kingpin both with hydrocopper blocks using a 9900k, protium pump res/d5 pump push only setup with ek varder fans and a ek monoblock for CPU. I plan on overclocking both CPU and GPU mildly probably 5.0ghz all cores on CPU maybe if it'll do it and 2000mhz on GPU's as well will this be enough rad for it. Everyone says 25mm 240 rad per component, I feel like that's about what I have with 2 360rads one being 30mm thick the other being 50mm thick 45yrs old first PC ever(console guy) be gentle with me

Here's a list of everything I have,rog extreme z390,9900k,two sticks of nvme, 2 2080tis,corsair ax1600i, 32gb corsair dominator platinum rgb 3200mhz cl 14,14,14,34 4x8, rog helios PC case. Mostly a gaming PC but extreme oc is something interested in down the road when I learn more. I knew that running two cards would drop x8 but from everthing learned gaming shouldn't be affected much? Only planned on using the 2 nvme slots on the board and the dimm.2 slot for storage but leaving it turned off when not in use the other two for games and os/boot up I know using the dimm.2 card drops lanes to x8 but like I said using for storage/backup. That being said it sounds like I'm kinda screwed on my board and CPU from what I read in your post may run single card for now and get the new primochill test bench when it comes out also the AMD 3950x sounds really appealing may get it when it comes out with a good x570 board

Rog maximus extreme xi is correct also I have the evga audio note, looks like i might be running one card for the time being

You need a HEDT CPU for more lanes.  Your CPU's 16 PCIe lanes won't cut it.
 
As for your cooling potential, that's more than enough rad for a system like yours.  Just make sure to feed those rads with some cool ambient air.
 
Also, google your case with the terms "custom cooling" to see what others have done with said case.

Yes, Slot 1 will Drop to X8.

Unfortunately I haven't been able to find any custom loop builds in the helios yet it's only been out for a couple months though. Also if a GPU is running in x8 lanes how much performance loss is their in gaming?

Your help Is golden i appreciate it very much , did a little more research on my mobo using the two m.2 slots on the board goes through the pch which has 20 lanes wont get maximum performance from my 970 evos but dont think it'll matter much still get to keep all 16 CPU lanes as for the dimm.2 it does use 8 CPU lanes so I wont be using it but that's ok, I can still sli even though it'll x8 should still get a good bump in 4k gaming at until I get a CPU and mobo with more lanes probably do that when primochill comes out with their new wet bench. As for my case the issue I found with using a 420 rad up front is you can only put it with the ports up top no clearance to put them at the bottom so that I could use a t fitting for easy draining not a huge deal though. Earlier you mention running dual pumps, is a d5 not enough to push through 2 GPU's and cpu

Probably do res/pump-rad-rad-gpu-cpu-res/pump it depends what's looks cleanest and easiest to maintain all soft tube biggest I can use, I've heard some people say not to go CPU to GPU or vice versa but the way i understand it is the loop stays at a constant temp same with the blocks because of the rate of water flowing is somewhat fast that you're not really seeing any heatsoke from block to block maybe a little but that would level out quickly in high flow rates. It is a tight fit inside but not gonna use the psu shroud or cable shroud, caselabs makes 420mmx54mm thick that has a total height of 452mm I think I'll try up front with 3 ek vardar furious 140mm static pressure fans max speed 2500rpm and 360mmx30mm thick rad up top and ek vardars 3000rpm max dont care about noise I'm a 45 yr old construction worker my hearing ain't great plus I'll be using headphones most the time

Guess I'll change the order but why no on rad to rad. Ekwb makes high rpm static pressure fans called vardar furious, 3 140s up front, 3 120s top, 1 140 in rear for exhaust, top and front intake for a static pressure setup I have dusty old house

Palerideher
Guess I'll change the order but why no on rad to rad. Ekwb makes high rpm static pressure fans called vardar furious, 3 140s up front, 3 120s top, 1 140 in rear for exhaust, top and front intake for a static pressure setup I have dusty old house

Silverstone Tek 120mm Ultra Fine Fan Filter with Magnet Cooling FF123B (Black) Works Wonders
Silverstone Tek 140mm Ultra Fine Fan Filter with Magnet Cooling FF143B (Black)