My 85 roc s temp gage has not work since i put my 350 in it . I think the problem is the part that the harnes plugs into on the t-stat . What is the correct name for this part and can i get it at napa or any other parts place.If you have any other sugestions, on what I mite want to check please give .oh i forgot to mention that i changed the intake and ditch all the emisions crap to

 

The guage is operated by the temperature sending unit. There should be a single green wire connected to it (it's been that same wire since the '50s). You should be able to connect this green wire to a good ground and force the temperature guage to read full scale. If not, there may be a power problern to the guage itself. The GAGE fuse operates that, and several other things, including all the "ditched emisions crap". May be relevant.