Help! Fuel tank questions.

[1trickpony]

I am elbow deep in an efi swap. My car is/was a 84 gt 5.0h.o 5 spd. Going to a 87 efi 5.0h.o t-bird motor.
My question(s)
1. Can I keep my fuel tank and just swap in the fuel pump/sender in the 84 tank.
1a. Can I utilize the existing fuel lines?

2. If above does not work. I think I could swap in 87+ tank/fuel pump in.
2a. Would I be able to utilize the fuel lines?

3. I have thought about just going to an in-line pump similar to my dad's hot rod. Easy to fix on the side of the road.


I just need to clear this up so I can order parts and get my pony on the road.
Any help is really apprecieted .

[TWR2003]

Assuming your 84 was originally carbd then no you cannot put a EFI fuel pump into that tank. The carb and CFI/EFI tanks were different from that standpoint. The CFI/EFI tank is a bolt in and are available new. They were used from 83-97 and will fit any 81-97 Mustang. You will need the stock (or stock type aftermarket) EFI fuel lines or you will need make your own. You will also need the late 86+ 5.0L EFI fuel pump assembly and proper fuel gauge sender. The pump assy is still available new. The sender you need with that tank was only used on CFI/EFI 83-86 and is now obsolete. The 87+ sender will physically fit but has the wrong resistence curve for the pre 87 fuel gauge. If you go with an external pump setup you could use your carb tank and stock sender but will need to have a way to plumb in the return line. We have seen lots of folks do it that way. Whatever you do DO NOT mickey mouse your fuel delivery system which is pressurized with gasoline at 40psi.

Good luck

[zac_f83]

why go through the trouble of swapping pumps when the tank has to come out to do the pump anyway??- like said it's not gonna work anyway (EFI pump in the 84 cab tank)

I would use the EFI lines- they go up the pass. side to the fuel rails instead of crossing over to the driver side midway (carb car's) for the mechanical pump

[4eyed83]

So if I have a 83 coupe with a carb, I can swap the tank to a 87-97 EFI tank? I am worried about the size difference and fitting under car.

[vdubn]

So if I have a 83 coupe with a carb, I can swap the tank to a 87-97 EFI tank? I am worried about the size difference and fitting under car.

They are the same size and are a bolt-in, as mentioned above.

To the original poster... I have a thread that outlined the installation of the fuel lines, as I just swapped my 85 over to EFI fuel lines, and fuel tank, and am in the process of swapping all of the harnesses from an 86 over as well.

http://vb.foureyedpride.com/showthre...Swap-questions

At the last page for now, Page 4 I think, I laid out all of the wiring harnesses that you will want, and why. There are a number of ways to do the swap, but through lots of research, and great advice here, I describe the cleanest way to make it look like EFI came in the car from the factory.

Good luck, its lots of fun.

[4eyed83]

Thanks vdubn. I thought so but just wanted to make sure!!!

[mustangxtreme]

I used an 87 Mustang EFI tank and lines in my 83L. The fuel pump harness and the ecu harness were also from the same car. The engine harness and computer were from the 88 T-bird.