I have an 87 camaro with an 85 mph spedo and i want to put in a 115 mph speedo. How do i do it?

Take out the old, put in the new. Take off the bezel, unbolt the cluster, unplug the cluster, and reverse the process. You'll need a torx bit to get the job done.

Yes it's a direct swap, but getting it done is a little more complicated.

Cause i took of the front and got off the face plate and behind the face plate is that little plastic piece that tells you the mileage and trip but that isnt what determines your speed so what do i actually have to change out. Cause all i could see behind the face plate and the little plastic mileage thing was a piece of metal? Cauld use more specific details.

its a little differnet but i swapped a 140 into replace my 85 in my ta, the swap was pretty straight forward, but you have to change the odometer assembly as well so you have accutate mileage.

So if i replace the face plate and the little plastic assembly thats behind it that has the trip and odometer on it is that it?

Ok, if you've got the face off, you've gone wrong already.

1. Take out the hush panel under the dash.
2. Unbolt the lower trim under the steering column.
3. Loosen the steering column bolts and let the column hang down.
4. Take the bezel around the gauges off.
5. Take out the two nuts at the bottom of the instrument carrier and pull the carrier forward slightly.
6. Reach behind the carrier and depress the clip holding the speedometer cable housing in place until the carrier comes free.
7. Remove the optical sensor for the VSS from the back of the speedometer.
8. Remove the screws holding the speedometer into the carrier.

Reinstallation is the reverse of disassembly.

If you want to swap the odometer, that's easy enough to do, too.