Rear underbed gas tank conversion

[wally426ci]

I think Kaegi means he posted his pic in the wrong spot.

[medic1241]

I like the idea of the Bronco fuel tank... Should I also invest in the sending unit designed for it as well? Thanks, Mike


1967 W-200 Sweptline 318 (parts donor)
1967 W-200 Sweptline 383 (I am restoring this one)
2003 DODGE 3500 SLT 4x4 Cummins

[JimE]

I did Surfnuke's build on my 70 camper special, the only sending unit that will work has to be made for the truck. Remove the original (if it still works) and follow Surfnukes instructions on shortening it. Jim

[soopernaut]

I did Surfnuke's build on my 70 camper special, the only sending unit that will work has to be made for the truck.

I think it has to work with the fuel gauge and is based on the resistance. If you have a different/aftermarket gauge then use the sending unit designed for that gauge. Of course the arm has to have the correct length for the tank too.

[Nuthinbutmopar]

I came upon a mid-70's C-body tank in great condition that should be hung under the rear soon. I'm wondering what you guys do about the hole from the neck in the cab. I vaguely remember somebody having an early lifestyle truck that had a rubber plug where the neck should have been, since the truck had saddle tanks; is there something like that available? Do you just leave the neck there? I'm not doing bodywork right now, so welding in a plug and finishing it is not possible...

[surfnuke9]

I just left the neck in there on mine.

[reallylongnickname]

I've been following this thread with great interest because I need to install fuel tank(s) and was considering this poly tank as well. However, I'm real confused at appears a yeild of two conclusions. I probably don't know half as much of any of you, but I need to know where I stand on fuel tank installation possibilies.

Firstly; Aug 2009, Surfnuke9 states that Ford sending unit is compatible with Dodge fuel gauge. That's what appears to be implied.
Secondly;Nov 12, 2011 JimE and Soopernaut come along and contradict the Ford to Dodge compatibility.

I found this poly Ford Bronco tank online and have bought one.
Benefits: 33 Gallon capacity, Ford fuel sender operates at virtually the same resistance range as Dodge (10 Ohms Empty, 75 Ohms Full), its a Poly tank and everything is new. Aug 20, 2009

I did Surfnuke's build on my 70 camper special, the only sending unit that will work has to be made for the truck.

I think it has to work with the fuel gauge and is based on the resistance. If you have a different/aftermarket gauge then use the sending unit designed for that gauge. Of course the arm has to have the correct length for the tank too. Nov 12, 2011

[JimE]

I'm not educated enough to know the difference between Ford and Mopar fuel gauges. I am going to have to loosen the bed to get a ground wire from the tank to a ground, as I forgot about it when I had the bed off. Its a hoot to go 325 miles without filling up though. Jim

[surfnuke9]

The ford and dodge sending units are very close on the resistance values.

Our sedning unit is about 7 ohms full and 75 or so empty. The ford unit is about 10 ohms full and around the same empty value as ours.

Turned out the sedning unit I got when I ordered mine was around 230 ohms empty and 10 full. didnt work for the gage, so in went my stock sending unit modified as stated earlier in this post.

By the way, my sending unit is still working just fine.

[soopernaut]

Secondly;Nov 12, 2011 JimE and Soopernaut come along and contradict the Ford to Dodge compatibility.

I did not contradict the compatibility of the sending unit between a Ford and Dodge. I stated that the gauge, sending unit and tank all have to be compatible. The arm that measures the fuel level has to be the correct length. The sending unit resistance between full and empty has to be compatible with the fuel gauge. Perhaps the Ford and Dodge parts are similar but I cannot verify without research.

[surfnuke9]

The sending unit from a Bronco up to 1977 is 73 ohms empty...10 ohms full.

Our trucks are around 75 ohms empty and 7 ohms full.

[reallylongnickname]

http://ecat.spectrapremium.com regarding fuel sending unit electrical values ONLY. Slightly out of caliber with the fuel gauge by aout 3 - 5 ohms is usually ok because you have tolerance on each side of the value, but it depends on your fuel gauge as well. The actually mounting location and length of rod is NOT listed.
FG161A FG61A FG61B FG62A FG71A FG72A FG73A
FG74A FG75A FG86A FG86B FG86C FG87A FG162A
FG86D FG173A FG178A FG179A FG179B

1964-1978 Ford Mustang................................ 75-10 ohms
1975-1985 Ford Econoline............................... 80-10 ohms
1973-1984 Ford F100, F150, F250, F350.............. 80-10 ohms
1974-1983 Jeep Cherokee............................... 75-10 ohms
1970-1979 Jeep Wagoneer.............................. 75-10 ohms
1978-1976 Jeep CJ5, CJ7, Scrambler.................. 80-10 ohms
1977-1983 Dodge B100, B200, B300 ................... 80-10 ohms
1981-1987 Dodge B150, B250, B350
1979-1989 Dodge: Aspen, Diplomat, Mirada........... 80-10 ohms
1980-1983 Plymouth Voyageur
1979-1986 Plymouth; Caravelle. Volare, Gran Fury.... 80-10 ohms
1969-1973 Mercury Cougar............................... 75-10 ohms

[reallylongnickname]

The stock fuel sender is working great. All I had to do was put a "Z" bend in the float rod and cut about 1 1/4" off the pickup tube.

What about the actual installation part though? What did you do about the retainer ring and hole diameter? Any modifications needed?

[surfnuke9]

No mods needed. The bronc tank hole size is the same as on our trucks.

[earlymopar]

I'm interested in this thread even though its over a year old.....

The use of a "Bronco" (up to 77') fuel sending unit is a nice alternative. However, the problem is that there are at least (3) Bronco tanks in the year range and I'm not sure which sending unit was used (regular tank, optional rear mount and, auxillary).

Clarification would be helpful.

Thank you,

- EM

[JimE]

EM, this is the tank he is refering to: http://www.trexautoparts.com/mm5/mercha ... y_Code=FBD
Jim

[mikesdodge]

Will the sending unit in the mustang tank operate the original gas gage in the Dodge pickup properly

[vabchmopar]

was the truck you placed the mustang tank in a long bed? I only have 11 inches from the rear cross member to the end of the truck frame. The mustang tank is twice that long

[MadMC63]

For anyone who is interested… The larger 22-gallon mustang gas tank will not fit in the same way without serious modification or removal of the frame cross brace. The 16-gallon tank is 7.5 " top to bottom and the 69-70 22 gallon tank is 9.75" top to bottom, two inches taller. The frame cross member is located between the rear spring perches and the brace is there for a reason. The brace reinforces the frame to keep it from twisting under a heavy load.

[Conrad]

That’s good info. I plan on moving my tank back there at some point. I’d love to have that extra capacity but also conceded that I’d be using the smaller one from Tanks with internal baffles.