Custom GMC Sonoma with LS3 V8 Engine Swap

Back in the day, GMC Sonoma and its twin brother Chevy S10 were incredibly popular on the mini truck scene. Offering the classic regular cab, short bed layout they attracted enthusiasts who wanted a cool looking street truck that’s affordable to own and easy to customize. Even though there were tons of aftermarket mods available for these trucks, they never stood a chance to be on the same line with the muscle cars, and the reason for that was the absence of the V8s in the model line up (perhaps due to the possible competition with Silverado full-size trucks).

Justin Hayward, the owner of this truck decided to fix this flaw and swapped the stock Vortec V6 on his 2003 GMC sonoma with a 6.2L LS3 V8 often found in Corvettes. Read on to find out more on the modifications and upgrades he did to this street truck from early 2000s!

The Build

Choosing the right engine to start your modification process with is a big deal, because it defines the HP range you will be able to reach. Obviously the numbers wouldn’t be that impressive if Justin would have kept the factory 4.3L Vortec 4300 engine. Even a supercharger would not allow you to go too far from the stock 180-190HP. That’s why he chose a complete engine swap.

Performance

As I mentioned above, under the hood of this blue street truck you’ll find nothing other than a big and mighty 6.2L LS3 V8 motor which hardly fits the engine bay. Up on top is the Stage 4 Brian Tooley racing cam, which along with the Stainless Works long tube headers feeding and custom 3″ exhaust system provide the perfect balance of the exhaust gas flow and sound.

The upgraded 8.8 rear end sourced from a Ford Explorer was a brilliant choice, providing the durability needed to handle the substantially bumped up torque.

Suspension and Wheels

The truck sits low on fully adjustable QA1 suspension adding enough stiffness for the front end which now carries a much heavier engine and levels the truck up on the back. Cal Tracs Traction Bars eliminate wheel hop during hard launches, contributing to those impressive quarter-mile times.

This dual-purpose build runs two distinct wheel setups – street duties handled by 18×4.5 front/15×10 rear Weld S71 RTS wheels wrapped in Mickey Thompson rubber, while serious drag strip sessions utilize 15″ Moroso DS2 fronts and Hoosier slicks measuring 28x10x15 on the rear.

Exterior

The exterior remained relatively stock, highlighting the original body lines of this good-looking truck. The rare Checkmate stepside flush mount tonneau cover along with the Step Shaver roll pan and shaved tailgate add that clean rear end look.

Up front is the GMC Envoy bumper, a detail only dedicated S10/Sonoma fans will notice, much like the sleek Street Scene mirrors. The 2″ cowl hood with functional Trackspec vents not only makes it look more muscular but serves the practical purpose of evacuating engine bay heat during drag launches.

Specs & Mods: 1998 GMC Sonoma

Performance

• 6.2L LS3 corvette Motor
• Stage 4 Brian Tooley racing cam,
• Stainless Works long tube headers
• Full custom 3” exhaust done by Brows exhaust
• 8.8 Rear end out of a Ford Explorer

¼ Mile 11.1 @ 121mph in 95 degree weather

Suspension

• Fully adjustable QA1 suspension
• Cal Tracs Traction Bars

Wheels

• Street setup:
  18×4.5 Front Weld s71 RTS wheels and 15×10 on the rear with 275/60/15 Mickey Thompson ET Streets
• Drag setup:
  15×4 with Moroso Ds2 tires and 15×10 rears with Hoosier 28x10x15 slicks

Exterior

• Custom blue color
• Checkmate stepside flush mount tonneau cover (very rare)
• Step shaver roll pan by Street Scene
• Shaved tailgate
• Street Scene mirrors
• GMC Envoy front bumper
• 2” cowl hood with trackspec hood vents

Conclusion

Performance mods dominate this build with a perfect 10/10 score, highlighted by the transformative LS3 Corvette engine swap that delivers musclecar-rivaling quarter-mile times. The suspension earns a matching 10/10 rating through its race-ready QA1 setup and traction-enhancing Cal Tracs bars, proving this isn’t just a show truck built for appearances.

With meticulous attention paid to both performance engineering and exterior aesthetics (scoring 8/10), this Sonoma makes a cut the muscle car scene with old-school looks and incredible V8 swap.