Alright, so I've been searching for the past couple days and I can't find a straight answer. Is there a difference between the sending unit for the gauge and the one for the light, or are they both the same?

 

Yes they are different. If you have a gauge on the dash and you put the on for a light you gauge will peg out. They are not interchangeable. I hope that answers your question.

 

Thank you. Now my issue is that autozone only has one and it doesn't say whether its for the light or the gauge. Do you, or anyone else for that matter, know a part number or where I can find the one for a gauge?

 

What size engine in you 87 and do you have the light or gauge on your dash? You may want to check out rockauto.com

 

4.0. It originally came with the light but I swapped the cluster. I had a mechanical gauge in there, but I want to go back to original gauges if I can.

 

If you're going back to the original cluster with the light, then you have to get the sending unit for the light.