my speedometer is screwed up in my '84 Silverado Blazer. I was wondering if there is a 100 mph or 120 mph speedo available for a direct swap. Also, Can I wire up a factory tach? where does my fuel gauge go? In the clock? I've never seen a factory tach, but I've been told they go in the right hand large spot where my fuel gauge is. How do they wire up? Anything special? Is there anywhere I can get these replacement gauges?