At any speed my speedometer will jump around about 5-10 mph over nad under what im actually going. I tried changing the speed sensor in the rear end but that did not help. Do you all have any suggestions i think either my comp is going cazy or my gauge is messed up. Also at the same time my fuel gauge quit working i have dual tanks on the same gauge and 1 registers and the other doesnt but even the one that registers gives me faulty readings. Plz help.

 

Sounds like the speedo head. Bad news is that you have to basically replace the entire instrument panel = $$ I had the same problem on my 96 when I bought it and it would up costing $370 for the new head + they sent the wrong one multiple times, but I blame that on my dealer's crappy service & parts dept.