Skip to product information
EFI-ready baffled fuel tank for 1978–87 Chevy/GMC Squarebody by Tanks Inc., short & long bed
1/5

EFI Fuel Tank — 1978–87 Chevy/GMC Squarebody (Short & Long Bed) + Pump Options Tanks Inc.

$589.99
Free Shipping $99+Free Shipping $99+ Lifetime WarrantyLifetime Warranty Expert SupportExpert Support

Reliable shipping

 

EFI-Ready Fuel Tanks for 1978–87 Chevy/GMC Squarebody (Short & Long Bed)

Rock-solid fuel delivery for EFI and LS swaps. These die-stamped, alloy-coated steel tanks add a 4.8 L dual-tube baffled tray to keep the pickup covered in corners and hard stops.

Result: easier hot starts, steady idle, and no fuel-starve on launch. Looks OE under the bed, drives like modern EFI.

How to order: choose your Year/Bed fitment below, then pick the GPA in-tank pump flow that matches your horsepower. You can add a 5-bolt sender now or later—your call.

Note: GPA-4 is the most popular pump option featuring a Walbro 255LPh pump

Fuel pump outlets are 1/4 NPT - select the correct NPT to AN adapter for your matching hose kit. Here 

  • ✅ Baffled EFI tray (4.8 L) controls slosh
  • ✅ Quiet in-tank pump options (109–450 LPH)
  • ✅ OE-style fit: in stock location
  • ✅ Powder-coated, corrosion-resistant steel

Fitment at a Glance

1978–81 Short Bed

Part: TM11A-T
Capacity: 16 gal
Size: 42-7/8" × 14-1/8" × 11"
Filler neck: 1-1/4"
Sender: 5-bolt

1978–81 Long Bed

Part: TM1A-T
Capacity: 20 gal
Size: 56" × 14-1/8" × 11"
Filler neck: 1-1/4"
Sender: 5-bolt

1982–87 Short Bed

Part: TM11B-T
Capacity: 16 gal
Size: 42-7/8" × 14-1/8" × 11"
Filler neck: 1-5/8"
Sender: 5-bolt

1982–87 Long Bed (also 1988–91 R/V)

Part: TM1B-T
Capacity: 20 gal
Size: 56" × 14-1/8" × 11"
Filler neck: 1-5/8"
Sender: 5-bolt

🛠️ Pick your fitment (78–81 or 82–87, short/long), then pick your pump (quiet, EFI-stable, sized for your build). Less heat, less noise, more reliability.


Choose Your In-Tank Pump (GPA Series)

All modules drop into the built-in tray and use 1/4" NPT feed/return ports. Up to 100 PSI capability. Gerotor pumps—disable PWM control on systems like FiTech.

Pump Flow Best For Power Guide* Notes
GPA-TBI 109 LPH TBI / low-pressure EFI ~ up to 250–300 hp ~15–20 PSI max
GPA-2 190 LPH Mild EFI & NA builds Up to ~450 hp Up to 100 PSI; 1/4" NPT
GPA-4 255 LPH Most LS swaps (58–60 PSI) Up to ~630 hp (gasoline) Disable PWM; 1/4" NPT
GPA-5 340 LPH Higher output builds ~700–800+ hp High-flow; up to 100 PSI
GPA-6 450 LPH Forced-induction / room to grow 800+ hp (setup-dependent) High-flow; up to 100 PSI

*Power estimates assume gasoline at typical EFI pressure; injector size, base pressure, voltage, and duty cycle affect real output.

Specs & Fitment

Short Bed (6')

Years Part # Capacity Dimensions (L × W × H) Filler Neck Notes
1978–81 TM11A-T 16 gal 42-7/8" × 14-1/8" × 11" 1-1/4" Baffled tray; 5-bolt sender
1982–87 TM11B-T 16 gal 42-7/8" × 14-1/8" × 11" 1-5/8" Baffled tray; 5-bolt sender

Long Bed (8')

Years Part # Capacity Dimensions (L × W × H) Filler Neck Notes
1978–81 TM1A-T 20 gal 56" × 14-1/8" × 11" 1-1/4" Baffled tray; 5-bolt sender
1982–87 (1988–91 R/V) TM1B-T 20 gal 56" × 14-1/8" × 11" 1-5/8" Baffled tray; 5-bolt sender

What’s Included

  • EFI-ready coated steel tank in your selected fitment
  • GPA in-tank pump module (if selected)
  • 5-bolt fuel level sender (if selected)

Recommended Add-Ons

Install Notes

  • Mounts in the stock saddle-tank location (ahead of rear axle). 
  • Sender pattern: 5-bolt. Tube or reed senders use 10" length for these tanks.
  • PWM: GPA gerotor pumps are not PWM compatible—disable pump PWM on systems that offer it (e.g., FiTech).
  • Plumbing: GPA modules use 1/4" NPT feed/return ports; vent is barbed.
  • Emissions: replacement-part use only where required; does not modify emissions equipment.

FAQs

Which pump should I choose?
For most LS swaps at 58–60 PSI, choose GPA-4 (255 LPH)—quiet, reliable, and supports ~630 hp on gasoline. Bigger power or boost? Step to GPA-5 or GPA-6. TBI or low-pressure systems can use GPA-TBI.
Will my factory gauge work?
Yes. Select a 0–90 Ω 5-bolt sender for stock GM gauges, or match your aftermarket gauge’s ohm range.
What’s the difference between 1978–81 and 1982–87 tanks?
Early tanks use a 1-1/4" filler neck; later use 1-5/8". Short is 16 gal; long is 20 gal. The 82–87 long-bed tank also covers 1988–91 R/V.
Shipping
Most orders ship within 1–2 business days. Free shipping on $99+ to the contiguous U.S.
Returns
Uninstalled items in original packaging are eligible for returns per our policy. Contact support for an RMA.
Quality
Die-stamped steel tanks with internal baffling and durable powder coat. GPA modules use genuine high-quality pumps and 1/4" NPT ports.

Customer Reviews

Be the first to write a review
0%
(0)
0%
(0)
0%
(0)
0%
(0)
0%
(0)

You may also like