I have a 86 IROC Z28, i was replacing my Coolant temp sensor on my 305 TPI. When i was taking it off there was another sensor in the front of the block next to my Temp sensor. I nor anyone else know what it is. It looks to be like another type of temp sensor. Can anyone help me out?

Could you post a pic? My first guess without even searching anything out. The fan relay. If its right next to the temp sensor it might be the rely to tell the fans when to go on and off. You have electric fans right?