Fuel Tank

[pilotXC]

As I start my swap, I'm wondering is there any reason why no one uses the mid 90's side mount gas tanks? Do they not fit in the older style trucks? I don't like the rear mount tank hanging down and don't want a bed fill either, so curious why no on seems to do side mounted tanks as GM did/does on trucks?

[ls1nova71]

Not sure what year truck you have, but unless it's an auxiliary tank, they dont fit on a 67-72 and auxiliary tanks are kind of small.

[sweetk30]

x2 on a LOT more info of your vehicle required .

88-up new body trucks went inboard of frame and the frame bows out the further back it goes after the cab so there not a easy fit at all .

if square body 73-87 then just get a 1987 tank for short or long bed for factory tbi injection . then a tbi sender unit minus pump . then a acdelco ep381 pump from a 1996 c3500 5.7L is a direct swap and has the psi and flow to get you started on the efi swap . or ask the place your getting efi from what pump they recommend to plug-n-play on the gm sender .

make sure you read and search a lot on efi there is good kits and bad kits . look real hard at the options and price points . learn from others troubles and try not to have the same happen to you . see my sig line below .

[pilotXC]

Thanks for the replies. The stock tank behind the seat isn't very big either, they are 16 or 17 gallons I believe, there is not a good option really for fuel tanks on the 67-72 trucks, in my opinion.

Mine is 72 K20, I'm installing an LQ4/4L80E and since I'm going to have to modify the stock tank behind the seat to work with EFI, I'm just trying to find the best possible solution that I like. I also have the dealer installed saddle tanks with the aluminum filler flaps. I'm good with the saddle tanks, and actually prefer them over the other options, but hate the aluminum filler flaps. But not sure how easy it would be to have 2 tanks with EFI... I assume using the 1987 control module would work and I could install separate internal pumps on both tanks?

[sweetk30]

i kept my truck stupid easy for me on efi and 2 tanks . driver side has high psi pump for efi and pass side has low psi tbi pump . i modified the wiring on the dash switch to just send power to the right tank pump when flipped right . i added a red light for when the pump is on to not forget and over fill . also the pump only gets power key hot so this is another safety . this seems to work good for me and no problems .

if you dont plan a ton of driving and high fuel use loads the 17-18 gal range tank will prob be good for you . i run my 20 gal tank for most of my driving . around town few towns over and no major drinking of fuel .

dont forget the in cab tank was never designed for return fuel flow so you might get unwanted fuel smell .

[pilotXC]

I"m confused on how to make 2 tanks work with the stock '72 gas gauge. I've read the threads here:

http://67-72chevytrucks.com/vboard/s...d.php?t=379708

http://67-72chevytrucks.com/vboard/s...d.php?t=674371

I'm still not sure how this would work or not on a '72. Sounds like most of the comments are around sq body trucks and using the '87 plumbing and selector, would the same set up work in a '72 without '87 tanks? So long as I had 60psi rated pumps in both tanks? How would the wiring harness tie in from the LQ4? Or would I wire in the existing fuel gauge to the harness somehow? Thanks for the help here, just trying to figure this all out...

[Captainfab]

Just to clarify. You are using the TBI pump in the passenger side tank to transfer fuel to the drivers side tank when needed? And the engine is fed fuel from the drivers side tank only?

Originally Posted by sweetk30

i kept my truck stupid easy for me on efi and 2 tanks . driver side has high psi pump for efi and pass side has low psi tbi pump . i modified the wiring on the dash switch to just send power to the right tank pump when flipped right . i added a red light for when the pump is on to not forget and over fill . also the pump only gets power key hot so this is another safety . this seems to work good for me and no problems .

if you dont plan a ton of driving and high fuel use loads the 17-18 gal range tank will prob be good for you . i run my 20 gal tank for most of my driving . around town few towns over and no major drinking of fuel .

dont forget the in cab tank was never designed for return fuel flow so you might get unwanted fuel smell .