oil light flickering at high rpm

So I have a built 340 with aluminum heads lunati voodoo cam etc. and my oil light starts flickering at around 4k if I have my foot on the floor. I have an aftermarket autometer oil pressure gauge and when hot I get 35psi at idle 75 psi cruising and 90-95 psi full throttle to 6200rpm. I run 20w50 valvoline vr1 oil that's topped off too. I'm wondering if the oil light sender isn't getting a proper reading because the aftermarket sender is using a t-fitting along with it. Anyone have this problem? I've uploaded a pic of my setup.