Howell EFI

Howell EFI Howell Engine Developments, Inc. As an adjunct to our wiring harnesses, we developed complete throttle body and multi-port fuel injection systems.

Howell Engine Developments' goal is to reduce the difficulty in adapting late model GM engines or fuel injection systems in older pre-computer vehicles of all types. was formed in 1988 by Bill and Matt Howell to support the growing trend towards the use of electronic fuel injection in the Hot Rod/Street Rod and Four Wheel Drive Industries. We combine proven GM electronic components, Howell wiring

harnesses, two and four-barrel TBI and TPI units. These systems offer GM closed-loop fuel and spark control, and typical GM durability and fuel economy.With extensive development on both big-block (454/502 CID) and small block (350/400 CID) engines, these systems are attractive updates for both hot rods, production carbureted vehicles, and off-road four wheel drive vehicles seeking performance and fuel economy. We choose to sell only the best quality components, and all are covered by a money back guarantee. We reserve the right to charge a restocking fee on all new parts returned. Our normal parts guarantee is replacement, if they fail within 90 days of service. On used or rebuilt parts such as ECMs, distributors, etc., our guarantee is for 6 months of service.

Howell EFI Annual Spring Tune Up Sale Extended Through Monday 4/6/26. Howell EFI Spring Tune Up sale is here and that me...
03/31/2026

Howell EFI Annual Spring Tune Up Sale Extended Through Monday 4/6/26. Howell EFI Spring Tune Up sale is here and that means 10% off everything on the website using coupon code: TUNEUP Now Through 4/6/26
*retail customers only* **10% Discount does not apply to dealer pricing or custom calibration programming** Shop now at: https://www.howellefi.com

NEWS & TECH VIDEOS BEST SELLERS NEW PRODUCTS

If you have a classic Jeep in California or other states/areas using CARB certification standards, has CARB certified ...
01/14/2026

If you have a classic Jeep in California or other states/areas using CARB certification standards, has CARB certified 50 state legal EFI conversion kits with CARB EO number(s). Visit our website for more info on our 50 state legal kits.

Now extended through 12/5 10% off everything on our website using coupon code BLACKFRIDAY at checkout
12/03/2025

Now extended through 12/5 10% off everything on our website using coupon code BLACKFRIDAY at checkout

NEWS & TECH VIDEOS BEST SELLERS NEW PRODUCTS

Now through 12/1 10% off everything on our website using coupon code BLACKFRIDAY at checkout
11/25/2025

Now through 12/1 10% off everything on our website using coupon code BLACKFRIDAY at checkout

Announcing our Spring Tune Up sale. 10% off everything on our website and free ground shipping on orders over $500 now t...
03/24/2025

Announcing our Spring Tune Up sale. 10% off everything on our website and free ground shipping on orders over $500 now through the end of March.

Happy Thanksgiving Everyone! 🦃 We're thankful for our wonderful customers and all their amazing project vehicles and wou...
11/27/2024

Happy Thanksgiving Everyone! 🦃 We're thankful for our wonderful customers and all their amazing project vehicles and would like to thank you all with our sale 10% off anything on our website plus free shipping for orders over $500 11/27-12/7 at howellefi.com

We have added to our line of Gen IV LS & Vortec harnesses.
10/08/2024

We have added to our line of Gen IV LS & Vortec harnesses.

Marine City, MI, (October 3, 2024) – Howell EFI, a leading manufacturer of electronic fuel injection conversions, announces new LS and LSA swap harnesses and components for Gen 4 LS based truck Vortec 4.8L, 5.3L, 6.0L, 6.2L, as well as the powerful LS7 7.0L and supercharged 6.2L LSA engines. New ...

10% off everything including LS/LT wiring harnesses and TBI conversion kits. Plus free shipping on orders over $500 at o...
03/05/2024

10% off everything including LS/LT wiring harnesses and TBI conversion kits. Plus free shipping on orders over $500 at our new website now through March 19. Use coupon code marchmadness at checkout.

NEWS & TECH VIDEOS BEST SELLERS NEW PRODUCTS

We recently built a new website and after the success of our holiday sale, we have decided to offer free domestic ground...
01/26/2024

We recently built a new website and after the success of our holiday sale, we have decided to offer free domestic ground shipping (to lower 48 states) for all orders over $500 even when we're not running a sale. So if you're interested in complete TBI conversion kit, LS or LT swap harnesses and other GM based EFI conversion harnesses and accessories then go visit: www.howellefi.com

Address

6201 Industrial Way
Marine City, MI
48039

Opening Hours

Monday 8:30am - 6pm
Tuesday 8:30am - 6pm
Wednesday 8:30am - 6pm
Thursday 8:30am - 6pm
Friday 8:30am - 6pm

Telephone

+18107655100

Website

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