Fuel tank sending unit

[rwhite65]

Ok, I have a feeling Rev will know this, but I need all the help out there in cyber space I can get. I am updating my fuel line this spring with the new pre- bent line I bought 3 years ago...figured it was about time to put on.

Here is the issue. If I put the new 3/8 line in place of the old 5/16, that leaves the sending unit as the weak link. I am not sure on what size the line is coming out of the tank, but what good is it going to do when I put a bigger line on, when I am still sucking from the same smaller tube? All the research I have done shows the same sending unit for the 65-68 cars. I can’t imagine the big block cars used the same line out of the tank.

Anyone dealt with this before? Any Suggestions?
thanks,
Ryan

[danford1]

The NPD catalog states that 65-68 senders all have 3/8" fittings used on 67-68's. Part number 9275-1A $24.95.

An article in Ford Muscle showed how they made there own 1/2" line. Simply cut out old line, drilled bigger hole, welded bent 1/2" steel tube in and reconnected (solder I think) fuel sending unit to tube.

Danford1

[Rev]

I still use the old 5/16" fuel line up to the engine compartment, then 3/8" to the carb. With 7-8 psi at the carb, I seem to be OK without any fuel starvation. I have often wondered what would be necessary if It needed 3/8" all the way through.

I think the alteration of the sending unit that danford1 describes is what would work to get the larger line from tank out to the fuel line. If the '67-68 sending units are actually 3/8", then I guess I would just try to use one and then just run a 3/8" from there on up to the engine.

What I can't seem to remember is if your engine is carbureted or if it's efi ? If efi, then we would be looking at a more complicated problem.

Rev

[rwhite65]

I am running a little ole 600 Holley right now, with no future plans of changing.

I guess maybe I jumped the gun. If the sending unit is already 3/8's, as long as it is not smaller then my fuel line I am ok with that. Guess when I get it out of storage I need to see what I have, then post
thanks guys,
Ryan

[SCHOONER]

Hey Ryan

I'm looking at the same situation for my '66, 289cid.
Everything is ALL APART right now (engine is stripped & hanging in mid-air on the engine hoist)

Got me a 4bbl carb. new intake manifold. I want to put in a 22gal. tank ~
(new from a 1970 'stang, they tell me with a few minor alterations it can be done. I want that extra 6gal. of juice. )

I read somewhere that; what's the use of having a bigger fuel tank. And have that gas being sucked thru a 5/16th line.

IT'S LIKE SUCKING A SODA THRU A COCKTAIL STRAW.

So, a friend of mine said, first get an ELECTRIC FUEL PUMP, then install the 3/8ths fuel line out of the bigger tank right up to the carb.

Ryan, that's what I hope to do.
Now, what have you found out about OUR SITUATIONS

Any and all help and knowledge you've got; PLUS all you other great guys will help me also.

Hope to hear from you.

Schooner

[rwhite65]

Schooner-
I initially thought a replacement sending unit came with a 5/16 line out of the tank. I have recently found out thanks to this thread that the replacement sending units have been bumped up to a 3/8 line outta the tank.

I bought a replacement 3/8 line to run from the sending unit to mechanical fuel pump (holley). I think this will be sufficient, unless I was gonna run something much aggresive then what I currently have.
I hope this helps,
Ryan

[Gearhead999]

SCHOONER,

It isn't necessary to run a 3/8 inch line for the engine combo you are going to be running. A 289 [4.6L] engine, 600 Holley, mild cam and build will have plenty of fuel from the 5/16 inch line. Also, just because the fuel tank will be bigger, doesn't mean that you automaticly need a larger supply line.

The larger fuel line is going to increase the "volume" of fuel that passes from the tank to the engine. Those 6 or so extra gallons aren't going to change that.

If you want to change the fuel line[s] to 3/8, by all means do it. You won't hurt a thing. But it is over kill for the engine you're going to run. Now....if it was a 428 cu.in. with an 850 cfm or dual 4-barrels....well that is something different.

Have a great day. Happy St. Patrick's day.

[rwhite65]

Schooner-
Gearhead999 is absolutely correct. I also believe it is over kill for your combo. I am planning on adding to my setup and believe some day it will be needed for me.

I also believe an electric fuel pump would be trick for you, but not needed.

Good luck-
Ryan