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.
