This is likely my sending unit right??? Thought maybe some other diagnostics might be in order. Here's the deal...twin 1986 454's FWC. The temp gauge on my last trip had a mind of its own. Port engine holds steady at 150-degrees regardless of rpm setting. However Stbd...holds 150-degrees at 2000 rpms but at 2500 starts bouncing between 140-160 degrees. at 3000 rpms it bounces around 130??? I have both upper and lower helm gauges (34 Tolly Sports Sedan) and the reading is the same at both stations. Could it be anything other than sending unit? Should I run a continuity check on the wiring? As always....appreciate the expert advice.