Fuel senders
The other thing, there is a product called "meter match" but unfortunately it was recently bought out and the prices went up. There is also a similar product on ebay. Sorry, I don't have the info handy. You have to get into the dash wiring, and this device goes electrically between the gauge and sender. It is programmable, and has several settings to correct the gauge vs the sender output.
Metermatch
https://www.technoversions.com/MeterMatch.html
Here ya go, the "other one" ---cannot believe I found that
https://www.forabodiesonly.com/mopa...rrector-cheaper-than-metermatch-33-00.517859/
The Egag link still works just under 30.00 I just ordered another one to play with