Tuning fix gauges?

Hey guys I swaped a 2004 ls5.3 and a 2005 4l65e into a 1998 GMC Sierra 4x4 with the Lextech pin out. My speedo, alternator, and oil pressure gauges work. How ever the fuel gauge is way past full but moves, no tach or engine temp gauge. Wondering what exactly has to be done so my local tuner can do this or do I need to mail the ecm to someone. Any help would be great thanks guys

You need to use the engine temp sensor that was on the original engine. And connect it to your gauges. As far as I know, there is no need to change anything in the tune for the engine temp. Now for the tach, they can change a signal from 8 to 4 or something like that.
This for your tach. http://www.lt1swap.com/lsx_tach.htm