not clear exactly what #4 and 5 mean, there should be zero ohms from any ground to any other ground, and no ground to the ignition post .... it may be that you don't have a "clean" ground and are adding the 25 or 60 ohms to the sender 'ohmage' - also make sure the gauge and cluster have good grounds to the dash, if things were painted before re-assembly you're adding ohms to the grounds
Bill
