i have a 79 k20 with an oem tank on the passanger side. the truck is stripped and set up for mud drags.. when i got it none of the gauges in the original cluster worked, and the fuel gauge would move with the turn signal lol... i tried another cluster and no go. is the sender on these trucks 0-90 ohm? i couldnt find much surfing online. i tested my sender and it seems to be working.