i jsut got an 87 iroc 305 5speed and the speedometer wasnt working along with the tachometer that was reading the rpms way high

the speedometer
i put it on a chassis lift and i saw the speedometer cable and i saw a electric sensor where it was right next to and i dont see anywhere else the cable goes. what should i check first?

the tachometer.
when im at 3000 rpm(im just assuming by the sound) its reading 6500 rpms.

where should i look at? what cna i do to get these components working properly?

thanks

 

What does the redline read on the tach?Just asking casue you might have a v6 tach instead of a v8

 

tach reads up to 7

 

Its very common for tachs to read very high as they get older. I had go go througj 4 tachs before I found one that worked. I even put in a v8 tach hoping it would would be wrong for a v8 ( meaning v8 tachs read low in a v6 car) but it was actually perfectly good for a v8, so it read too low on my car