Plumbing to gas tank

[c10beezer]

Can someone help me out here? I have a 68 c10 that I bought in pieces (someone elses project). I am running my fuel lines to the stock tank behind the seat. On the sending unit I have two lines 3/8 and I am guessing 1/4. The 3/8 would be the feed but would the return be that small? My carb return is a 3/8 line. My other question is on the passenger side of the tank there is a 3/8 fitting what is that for? Thanks for your help.

[c10beezer]

Am I the only crazy one who is going to run the stock tank?

[haysonj]

I'm not sure but I don't think that is a stock tank for a 68. My 69 only has the one line out of the sending unit and unless you have a big block it will not be 3/8

[cameeks]

Originally Posted by haysonj

I'm not sure but I don't think that is a stock tank for a 68. My 69 only has the one line out of the sending unit and unless you have a big block it will not be 3/8

all the tanks are 3/8 feed lines.

[Jim_PA]

Originally Posted by cameeks

all the tanks are 3/8 feed lines.

Mine is 5/16, currently in the process of upgrading to 3/8 with all new lines up to the carb.

[c10beezer]

It may be a later tank, the guy I got it from bought a wrecked 72 for parts.
Let me describe the tank an fittings a little better. There is a vent at the filler, sending unit has two lines 3/8 and about 1/4, passenger side of tank has another line in the corner it looks to be a little smaller than 3/8. Is ther a way for me to still use this?

[70inline6]

Originally Posted by c10beezer

It may be a later tank, the guy I got it from bought a wrecked 72 for parts.
Let me describe the tank an fittings a little better. There is a vent at the filler, sending unit has two lines 3/8 and about 1/4, passenger side of tank has another line in the corner it looks to be a little smaller than 3/8. Is ther a way for me to still use this?

You can still use it but as written, it is from a charcoal canister equipped vehicle. In my research, all V8's used the 3/8 sending unit line and the 6's used the 5/16. You can either cap the vents or plumb the sending unit and pass side vent (t'd) to a canister.

Don't plumb them directly to the carb or your tank will be under constant vacuum. It couldn't hurt to find a junk yard canister and plumb it in - I can smell fumes in my garage whenever I don't drive mine for a day or two.

[haysonj]

Originally Posted by cameeks

all the tanks are 3/8 feed lines.

If you look at the sending units on LMC only the big blocks are 3/8 the rest are 5/16 Just rechecked LMC I was wrong the two barrel carb is 5/16 and the four barrel is 3/8

[cameeks]

Originally Posted by haysonj

If you look at the sending units on LMC only the big blocks are 3/8 the rest are 5/16 Just rechecked LMC I was wrong the two barrel carb is 5/16 and the four barrel is 3/8

Umm



When I was searching for a tank I have never saw where they asked what size I needed and the one I got was 3/8. I stand with a foot in my mouth

[cameeks]

sounds like a tank from a truck with a charcoal canister. The 3/8 is the feed and the 1/4 would be the vent.

[cameeks]

Why couldnt he just cap off the other lines. My '69 tank only has one line out to the carb and that is factory.

[c10beezer]

Ok. if the line on the passenger side is for the canister filter, the smaller line on the sending unit is a return.? I really appreciate the help.