stock tank return sender

[firedemon]

I have been searching for a in the cab tank sending unit with a return line seems no one is making these . seems like with all the ls swaps someone would have thought of this . has anyone seen or know where to find one ?

[ncpetersc]

Originally Posted by firedemon

I have been searching for a in the cab tank sending unit with a return line seems no one is making these . seems like with all the ls swaps someone would have thought of this . has anyone seen or know where to find one ?

Look into a unit for a 1972 "with EEC" I think that has the return line you are talking about.

Like this maybe? http://www.manestruckparts.com/store...Category_ID=21

[firedemon]

I did see those but wasn't sure if it would work with a stock 67 tank . I know the filler neck is a diffrent size and uses a diffrent gasket to the body so am unsure if it has the same size sending unit .

[GMCPaul]

You can use 1972 fuel senders in 1967-71 fuel tanks without any modifications required other than dealing with the additional return line which wouldn't be a problem for you since you need a return line.
Paul Sr. @ GMCPauls

[Jrainman]

I used the 72 style sending unit on my 68 , but used the 72 style unit as intended (for venting ) for the return I installed a 3/8 bulk head fitting in the stock tank , you need to also vent a FI system that requires a return.

[Jrainman]

Here is a photo to give you a better idea, the bulk head fitting (return ) is installed to the left of the sending unit ,fitting installed in minutes .

[firedemon]

Originally Posted by GMCPaul

You can use 1972 fuel senders in 1967-71 fuel tanks without any modifications required other than dealing with the additional return line which wouldn't be a problem for you since you need a return line.
Paul Sr. @ GMCPauls

thanks

[firedemon]

Originally Posted by Jrainman

I used the 72 style sending unit on my 68 , but used the 72 style unit as intended (for venting ) for the return I installed a 3/8 bulk head fitting in the stock tank , you need to also vent a FI system that requires a return.

thanks im just running a carb want to run a electric pump the return will keep the noise down make the pump last longer and should prevent vapor lock . the cap vents real well so im hoping not to drill into the tank . I was just thinking the ls guys found something to keep the stock tank

[ncpetersc]

Originally Posted by Jrainman

I used the 72 style sending unit on my 68 , but used the 72 style unit as intended (for venting ) for the return I installed a 3/8 bulk head fitting in the stock tank , you need to also vent a FI system that requires a return.

I thought the second line on the sending line was a return line, and venting was achieved with a separate line through the vent tube in the cab, and back to the canister.

[Jrainman]

Originally Posted by ncpetersc

I thought the second line on the sending line was a return line, and venting was achieved with a separate line through the vent tube in the cab, and back to the canister.

Yes return line .but for the venting side of a 72 style fuel system, not actual liquid fuel return from the supply side , Witch the OP is trying to achieve in his stock 67 fuel tank . that has no venting other then the OEM fuel cap wich has a vent in it.

A 72 fuel cap has no venting because of emmisions standards that were placed and hence the venting drawing you posted

He is trying to mix and match as I Did in my photos because I needed to add a return line as wants to also, in my circimstance I added a fuel injected system that required a return line , I found that my 68 style vented fuel cap did not vent enough on its own thats why I added a separate return fitting to my 68 style tank and used a 72 style fuel sending unit that has a vent tube to add in the venting I needed to relive the extra pressure that occurs in a retun fuel style system ,

Even though the OP is still utilizing a carb he has added a electric fuel pump and a regulator to regulate the fuel pressure to suit the carb fuel pressure that is required , he feels by making a return style system that this will reduce his chances of having vapor lock in the fuel system because he understands that when you raise the pressure you rase the tempeture of the fuel ,

So his princaple theroy is to reduce the pressure and that will reduce tempeture therefore giving him a better chance of no occurance of A- vapor lock and B- running the electric pump at a lower tempeture will increase the longevity of the pump its self .

[ncpetersc]

Originally Posted by Jrainman

Yes return line .but for the venting side of a 72 style fuel system, not actual liquid fuel return from the supply side , Witch the OP is trying to achieve in his stock 67 fuel tank . that has no venting other then the OEM fuel cap wich has a vent in it.

A 72 fuel cap has no venting because of emmisions standards that were placed and hence the venting drawing you posted

He is trying to mix and match as I Did in my photos because I needed to add a return line as wants to also, in my circimstance I added a fuel injected system that required a return line , I found that my 68 style vented fuel cap did not vent enough on its own thats why I added a separate return fitting to my 68 style tank and used a 72 style fuel sending unit that has a vent tube to add in the venting I needed to relive the extra pressure that occurs in a retun fuel style system ,

Even though the OP is still utilizing a carb he has added a electric fuel pump and a regulator to regulate the fuel pressure to suit the carb fuel pressure that is required , he feels by making a return style system that this will reduce his chances of having vapor lock in the fuel system because he understands that when you raise the pressure you rase the tempeture of the fuel ,

So his princaple theroy is to reduce the pressure and that will reduce tempeture therefore giving him a better chance of no occurance of A- vapor lock and B- running the electric pump at a lower tempeture will increase the longevity of the pump its self .

Thanks. Another day, and something new learned. I had (falsely) assumed that is was actual fuel return, like if float needle was seated to avoid pressure buildup or something. Not the first time I've made a bad assumption, and won't be the last...

[Jrainman]

thats why we are here to learn and help