67-72 fuel tank sending unit question

[72freak]

I have always seen advertised V-8 sending units and 6 cyl sending unit. V-8 being a fatter fuel line and fittings. I am needing a couple so I have looked at my collection of trucks and the big block Longhorn has a big line sending unit (new) but all the rest of my original V-8 trucks have a smaller one. I know the trucks are original V-8 trucks so whats up?

Now....if you look in the LMC cataloge they designate 2bbl v/s 4bbl. instead of the V-8 v/s 6 cyl. That would make sense because I know all the trucls I have that I looked at were v8 2 bbl trucks and the Longhorn is a 4bbl.

looks like the big line is about 3/8 OD and the smaller line is just over 1/4.

Can anyone shine some light in this? i tried calling Christians trucks but all the phone numbers were not working.

[68gmsee]

Looks like you got it figured out. From what I know, bigger tubing is for the larger engines.

In my experience, it doesn't seem to make much difference unless you're into really heavy pulling or racing. I've converted from six to v-8 and kept the same tubing to the fuel pump without any problems. And that was using a 350 with a quadrajet and 350 th trns.

[72freak]

[QUOTE=68gmsee;3996803]Looks like you got it figured out. QUOTE]

Yep...the only probem is if I in fact have it figured out everyone selling them except LMC has it somewhat WRONG!

[GMCPaul]

Heres the info on sending units off of our web site,
67-72 Pickup in cab fuel sending units for 6 and 8 Cyl., Chevy and GMC trucks. Select Style in Cart.*
Style#1- 67-71 6Cyl. or 2bbl V-8,*
Style#2- 67-71 4bbl. V-8,*
Style#3- 72 6cyl or 8 Cyl. w/Man. Trans. w/EEC,**
Style#4- 72 6cyl. or 8 Cyl. w/Auto Trans.*w/EEC
NOTE: 67-71 trucks that originally came with a V-8 2bbl carburetor use a 5/16" fuel line and 67-71 trucks that came with a V-8 4bbl carburetor used a 3/8" fuel line. To ensure you order the correct fuel sender we recommend you check the size of fuel line on sender as many original 2bbl trucks have had the carburetor replaced with a 4bbl.*1972 EEC equipped trucks have a fuel vapor line on fuel sender.
GMCPaul Jr

[72freak]

Thanks Paul...do you have these (3) in stock and ready to ship?

V-8 2 bbl. 67-71

[tmilen]

[quote=72freak;3997349]

Originally Posted by 68gmsee

Looks like you got it figured out. QUOTE]

Yep...the only probem is if I in fact have it figured out everyone selling them except LMC has it somewhat WRONG!

is the 5/16" or 3/8" ID on the sending unit?

[jimijam00]

good question

[Andy4639]

This is the one out of the 67 ramp truck. I assume it's the original but can't say a 100%. It has singal line which looks to be 3/8" because the new fuel lines I got are 3/8" rubber hose to connect it up. You notice the sender has a coupling made to the line. The new one did not so I just cut the old line going through the floor off to except the rubber hose.
I couldn't find anyone who had the correct line with the coupler on it.

[72c20customcamper]

Originally Posted by Andy4639

This is the one out of the 67 ramp truck. I assume it's the original but can't say a 100%. It has singal line which looks to be 3/8" because the new fuel lines I got are 3/8" rubber hose to connect it up. You notice the sender has a coupling made to the line. The new one did not so I just cut the old line going through the floor off to except the rubber hose.
I couldn't find anyone who had the correct line with the coupler on it.

Looks just like the one on my stepper . I got the new one from parts geek fit perfectly. They had both 5/16 and 3/8 lines

[Andy4639]

Originally Posted by 72c20customcamper

Looks just like the one on my stepper . I got the new one from parts geek fit perfectly. They had both 5/16 and 3/8 lines

Well I never found it dang it man!

That's it though for sure.