1980 Sending Unit
 

Need to replace this sending unit 1980 K10 manual transmission. can I run a single tube sending unit or do I need a 2 or 3 tube? The smaller line runs to the front of the truck and is cut and crimped off. The other larger line runs up to the charcoal canister and is the only line hooked up to the canister. And of course the other line is the fuel supply line to the pump. Since basically 2 of the lines are not really connected to anything I dont see what it would hurt to use a single line sending unit. just would like some input before I order a new one. Thanks

Re: 1980 Sending Unit
 

The crimped off line would be return from fuel pump. You can use a sending unit without a return line as long as your fuel pump doesn’t have provision for a return line as well

Re: 1980 Sending Unit
 

3/8" - suction
5/16" - return
1/4" vent line


if using 1 single line and rest capped off make sure the cap is vented or you will build up a vac in the tank and have fuel feed problems.