Tempeture sensor doesn't work
 

When I was getting my headers installed I got pacesetter long tubes and we took out the old temp sensor that's off the block and that sensor was falling apart and my temp gauge worked before the install so I got another one and put it on and my temp gauge didn't work so I thought it was bad out of the box so later on I got another one and my gauge still doesn't work so I don't know what to do

did you plug the wires back into the sensor? are any of the wires melted or cut? if it worked before you put it in. and now it doesnt. then 1 you shouldnt have pulled a good working one in the first place lol. they are easy to swap so i wouldve left it in untill something went down hill with it. and 2 you could always try another one. i went through 4 MAF sensors before i found one that was reading right. sometimes you just get a bad pick of the straw

Follow the ECT sensor wire all the way back, make sure its not burned by the exhaust or a open wire. Make sure you don't have air in the cooling system, check coolant level make sure system is completely bled.

If you removed the old sensor most likely lost some coolant.

http://shbox.com/1/temp_sensor2.jpg

yea the plug is in and the wires arnt burned or cut plus i couldnt use the old sensor because the connection for the sensor broke so i went to winchester auto and got a new one and that didnt work then a little bit later i went to kragens and got another one and that one didnt work either and the coolant is full and when we took it out coolant did come out and i dont think air is in the system. so i dont know lol

Often the only sensor that works properly is an AC-Delco/GM sensor. For some reason, the parts houses are famous for giving out the wrong one.

1993-1997 coolant temperature sensor for gauge (single wire):
AC-Delco # 213-77
GM #25037332

http://shbox.com/1/4th_gen_tech2.html#ect

yea the ones i got were bwd i think