1973 k10 intellitronix fuel gauge issue

[Mike_The_Grad]

Hey everyone, i recently performed ls swap on my buddy's 73 k10. I also installed intellitronix analog gauges. I'm having issues with no voltage meter reading at all. Fuel level gauge is reading different readings all of the time. Sometimes needle is pointing straight down, sometimes 3/4 tank, sometimes 1/4 tank. All of this happens within a few minutes of driving. I ran out of gas on Friday and was stranded for 2 hours. Gauge was reading 1/4 tank. I'm using 87 tbi tank, 87 tbi sending unit with 255 lph walbro pump. Sending unit wiring is as follows. Sending unit ground with eyelet to frame rail clean no piant star washer nut and bolt. Pump harness 2 wire pigtail is fitech fuel pump relay wire to positive wire of fuel pump, negative wire of fuel pump is connected to signal wire of intellitronix fuel level gauges. Intellitronix fuel level gauge ground wire is connected to frame rail clean no piant star washer nut and bolt tight. Frame rail grounded to negative post of battery. Heavy duty ground straps from both cylinder heads to framerail, frame rail to battery negative post, cab to frame rail with ground straps. Fuel tank to frame rail with ground wire clean no paint and tight with star washer. Oil pressure gaugereads correctly and so does water temp gauge. Speedometer needs calibration and so does tach. But voltmeter gauge shows nothing all the time no matter what. Any help??