stock gauges suck

My work has found a guy that fixes things like gauges, (Hamps Speedometer Services) and this guy knows his stuff. We take things like speedo clusters to him all the time for accuracy issues and such. I asked him about our years cars' clusters. He said the best thing you can do is make sure the terminals/connections are free of corrosion and dirt, and they get proper voltage and ground, but besides that, we are out of luck. They were never very acurate to begin with.

I so agree with 2000xp8 on some points. I dissagree a bit about the tach thing though, because "feel" can be deceiving and the stock tach is known for being inaccurate and sometimes RPM is important. Also, if you have an engine that revvs past the stock tach's range.... well you are badass enough to have a aftermarket tach... just don't mount a huge one where everyone within 100 yards can see it and you can't see out. The fuel gauge accuracy is more determined by the sending unit and it's location, and it's limited to how accurate it can be, unless you were to put several senders in there and have a computer calculate exactly where the level was.

Gauges I feel are important as they car tell you what's going on in the engine are Fuel Pressure, Vacuum (boost if you have it), Oil Temprature, and Trans Temp if you have an auto.
 
I'm sitting here trying to have something "viable" to add, but I just don't.

All I can say is that I would agree w/ 2000XP8. (I know, I said agree) What you need to truly worry about in terms of accuracy comes down to two gauges. (OP and WT). All the rest in a street driven car comes down to keeping you moderately informed and if working properly, is close enough.
And if a tach is important for shifting, having a light flash is way more reliable than thinking you're gonna be able to watch a needle.