dakota digital dash

73 vette with VFD3 Dakota Digital display. 7 gauge package that fits into existing bezel and includes their own oil, water and vss sensors. speedo/tach display for driver that are working perfectly. Cluster of gauges in the center that are not. Volt meter reading correctly but oil flickers...

hooked up my dash in a 1953 chevy. ive moved the grounds around and back to the engine block. im still having issues with flilckering and incorrect mph, and engine temp. the link below is an example i video'd. any help or suggestions will be greatly appreciated. not sure if i got a bad unit...