So, over the weekend I replaced all the dash gauge light bulbs with LED bulbs in my '86 K5 Blazer. I was very carefull to not touch the needles on the speedo or the gas gauge. Everything went as planned the the lights work great. However, I am now noticing my gas gauge is way off. For example, after filling the gas tank to full, the gauge now shows way-way beyond full. So, now a real 1/2 tank of gas is about where the Full mark is on the gauge indicator. How the hell does that happen? Can these gas gauges be calibrated? Do I just move it backwards with my finger until I get it right? I'm open to suggestions. 
