85 Chevy truck rpm gauge troubles?

My truck RPM gauge isn't working, and my truck has trouble shifting.. Is the rpm gauge all electrical or does it have some mechanical purpose as well? Could it be that the gauge isn't plugged in and I have problems or is it possible that the two problems coincide? My transmission is a 700r4 and the engine is a Chevy 350 crate.. When i drive my rpm are at zero and sometimes hop to eight but the engine does not rev, just the stick moves. Also when my truck shifts it feels like the throttle hesitates to switch gears and i have to let off the gas and make it shift myself kind of.. the truck is automatic as well. Sorry about the messy questions. and thank you for your advice.