Well you do not have to drop the tank to remove the sender , and bending the sender arm will not ever being close to acorate in how much fuel you have in the tank , even brand new pintos would not because of the odd shape of the fuel tank is to blame , as for a sender for the 71 up pinto you can use a later unit but have to plug the extra return line , to make the fuel gauge read right you will have to add a gauge match unit and a new elctronic TVR behind the panel , or bypass it , the device is called Meter Match , after you install it between the sender and gauge ( I put mine in the pannel next to the headlight dimmer switch where the wires go to the tank ) and you start filling the empty tank and program 1/4 1/2 and 3/4 full on it , it also has a wire if you want a low fuel light to kick in when you set it , cost was around forty bucks , now when it says half a tank its realy half a tank , you might still find the write up I did a few yaers ago on this in the help section with photos , and my reply to mklarose is you are right , newr cars of today will not be around unless they end up barn finds later , my pinto is 45 years old and been updating parts in it and I can say it just like new , I keep it inside and only drive it on nice days when low trafic is there , it will out last me if runs for 34 more years ,( will be 100 by then ) just to give you a idea . hope this helps you , later Blaine