[SOLVED] Asus Gryphon Z87 Gpu problem red vga led and such

So after some trouble shooting on the forum with using a G3258 on this mobo i got another problem.
(Running with no GPU in any slot, on the iGPU it works)
The first PCIE 3.0/2.0 x16 slot cannot be used because of the cpu cooler.

When i put the gpu in the second PCIE 3.0/2.0 x16 slot the red VGA led stays solid and after a few seconds the Boot LED goes on and stays solid also.

When putting the gpu in the PCIE 2.0 x16 slot (wich wil only run @ 4x) i do get display from my GPU
and it workes,

But it's infront of several headers wich is very anoying and the 4x limitation is a deal breaker.
so how do i get it to run in the second PCIE 3.0/2.0 slot?

If someone comes along,
i fixed it by putting the 2nd pcie slot into gen2 mode in bios.
i don't know why.
i could have sworn that the 7850 was gen3.0 ready..
but oh well