1999 Chevy K1500 gauge problem

Having issues with the gauges in my truck. Usually only in the mornings, the tach will quit working and the speedo will go to 70 or 80 (this morning 100), the check gauges light comes on and the tranny is stuck usually in 3rd (auto). The indicator light for the gearshift (P,R,D,3,2,1) also goes out. I swapped out the fuel injector spider a while back and that’s when the problem began. Any thoughts?

If the spider assembly was replaced it means the intake manifold had to be removed.

I would go back and make sure any grounds from the engine to the firewall are still intact/tight.