i have a threadripper 1920x with 2x2080ti. When running cpuburn, i get around 65 tdie temp and with gpuburn, the upper card gets to around 86 and the lower one

i have a threadripper 1920x with 2x2080ti. When running cpuburn, i get around 65 tdie temp and with gpuburn, the upper card gets to around 86 and the lower one to 81. i have right now a water cooler for the cpu, 3 inlet fans (bottom back) and 2 outlet fans through the water cooler on top. i was wondering what temperatures I should aim for and what an optimal fan configuration is. i have a couple of fans laying around. the case is lian li O11 Air and the mobo is a taichi x399. anyone any tips? also I would want to use SLI. but then I would have to remove the fans on the gpu. Do I need then to water cool the gpu or what is the solution? if anyone of the moddibg pros here can help that would be awesome :-)