Custom Vehicle Upfitting and Assembly Solutions

We deliver custom vehicle upfits and high-quality assemblies built to your precise specifications. Every unit. Every time.

Interstate Assembly Systems is the home of:

Southwest Products LODI VH Trucks

Why We’re Different

With Interstate Assembly Systems, you’ll work with one company, not a collection of suppliers. Company leaders across industries rely on Interstate Assembly Systems to get the job done.

Experienced and efficient, our team provides customers with quality products and delivery schedules they can count on. From small equipment to complete vehicles, our assemblies and vehicle upfit projects will meet your short- and long-term business needs.

Assembly Solutions

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Assembly Solutions

Full, Sub & Final Stage Assembly
Line Entry Sequencing
In-Plant Production Support
Engineering & Product Development
FEA Design Testing
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Vehicle Upfitting

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Vehicle Upfitting

Spec Builds
Custom Builds
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ISODUNS RegisteredSAM Certified

Certified, Skilled, Committed

From assembly to vehicle upfitting, our staff and facilities are certified to meet all customer, statutory and regulatory requirements.

Our Quality Management System is certified to the ISO 9001:2015 Standard. We are also a SAM-registered entity (DUNS 928952332, CAGE 3FAJ1), allowing us to conduct business with government agencies.

We continue to develop and improve our process while strictly conforming to customer specifications and all applicable laws and industry regulations.

Extensive Options,
Custom Builds

Wallboard, material handling, mechanics, fuel and lube, and railroad, – you name the industry – we have your truck!

inventory options

Explore Rewarding Careers
With Interstate Assembly Systems.