[High ho silverado]

Don't know if this will help for the original post which was about a 91 gauge cluster, if u get a sender from a 99 firebird it has 3 wire terminals, u can get a pigtail too, the plugs are realllllllyyyy easy to take apart, jus hook the two factory wires in the same spot then use the third for your temp gauge, no adaptors or machining required and the ohms are the same, I did that on mine and it matches the computer reasons exactly and we have measured it with a infered gauge and is right on, hope this helps. Also that sender will fit on either head.