gauges

hey i just bought a 88 iroc z28 as the name lol, but my speedometer only reads about half of what im doing, im not to much into cars and im just wonderin if anyone know what to do to fix or do i have to get it replaced, the car is in good condition but theres a lot of minor details i have to fix. speedometer/tach, exhaust, and some wireing the stereo seemed to have been ripped out and the person seemed to want to use speaker wire to tryn and fix it and now theres a cluster of wires i have no clue what there for.

I have a speedometer I had posted on ebay for a while but the guy who 'bidded' for it didn't want it , I'd sell it off for what he bidded for it , 25.00 + shipping. It has white lay overs , 110 mph speed. 148K on the odo. 7K rpm with a 6K redline . It's not fried or anything and it all works. pm me if you want it , let me know.

Ps - New ones run about 300..lol.

Does the odometer work correctly? As in when you go 1 mile does it record 1 mile? If not you may have the wrong speedometer gear in the transmission.

lol whats funny is i used to make all the autometer gauges and tachs n shit where i used to work :s