Inaccurate C3 fuel reading

I have a 76 and the fuel guage is all over the map. It seems to be sticking.
It usually will read right off the map - full, full, full. Then If I stop or decelerate suddenly it will go down to where the normal
reading should be and I know how much gas I have. Sometimes it seems ok for awhile with proper reading and then it will start this again.
I did get a replacement fuel sender for this, but it looks like I have to drop the tank just to change fuel sending units and would like to be sure.
Any clues on what else I could check first?
TIA
PS. For anyone who was reading older posts I did get the new composite spring, shocks done and then recored the rad and replaced the rad support on it so that is all good to go now!
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Sounds like the ground wire to the tank and sending unit. Check for broken wire or corroded connection.
PDDeen
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think on that year I have to drop the tank just to do all of that, so I'd better have a replacement send unit on hand as well I guess.
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It needs a new sending unit. There is a resistor inside that slows the movement down that goes bad. Common occurance, my 81 has the same thing. I didn't think GM sold the sending unit.
If this were a Chysler Product the guy in the service department would have his most common response. "Yeah, they all do that"
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On Jul 9, 11:30 am, "Speaker of the Truth"

I picked up a sending unit from the US of A np. I do have to drop the tank on a 75-77 model, so it will be awhile before I get to it. Thanks. I'll check the grounds, etc when/if I am in there.
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