Flagship offer
Gen III HEMI Swaps
5.7, 6.1, 6.2, 6.4, 392, Scat Pack, and Hellcat-family swap planning for classic Mopar platforms.
View swap path
Chico, California performance shop
Modern HEMI Power for Classic American Muscle
4311 Performance builds, repairs, restores and modernizes high-performance Dodge and Plymouth Mopars from Northern California - serving local drivers and national HEMI swap customers.
- Flagship
- Gen III HEMI swaps
- Local Radius
- Northern California
- National Work
- Ship-in Mopar builds
Performance, restoration, repair
Built for serious muscle car owners who want the job done right.
Every section pushes a qualified next step: build estimate, repair booking, HEMI swap consultation or documented restoration.
Repair lane
Performance Repair
Diagnostics, drivability, brakes, cooling, suspension, electrical, and performance service for high-value street cars.
Book repairModernization
Drivability Upgrades
Modern fuel, ignition, charging, cooling, highway gearing, and reliability work without killing the car's character.
Start build reviewClassic body. modern heart.
Gen III HEMI swaps. Classic body, modern drivability.
Owners who want classic Mopar presence with modern HEMI power, better manners, stronger reliability, and a more usable highway car.
- Dodge, Plymouth, Cuda, Barracuda, Challenger, Charger, Road Runner, GTX, Duster, Dart, and Demon platforms
- 5.7, 6.1, 6.2, 6.4, 392, Scat Pack, and Hellcat-family planning language
- Build-dependent highway economy. Some streetable modern HEMI combinations can move from roughly 10-13 mpg toward 21+ mpg highway, depending on engine, gearing, tune, and use. Not a guarantee.
- Case-by-case smog, emissions, race-use, and off-road-use-only review for California-sensitive work
Documented builds
Classic Mopars. Built to drive.
Harold Tarter has been building, restoring, racing, and judging Mopars since 1983. He has served as a Concours d'Elegance judge since 1986, including five years at the Mopar Nationals and five years at Mopars at the Strip.
1974 Dodge Dart
1965 Dodge Dart
HEMI modernization, wiring, cooling, and drivability.
1970 Dodge Challenger
Performance repair, diagnostics, brakes, cooling, transmission, and suspension.
"I got 21+ MPG driving 70-75 all the way home."
Tim - Dart - Montana
"You're like an artist with this stuff."
Bill - Dart - Chico
"This is what I hoped for!"
Jakestr - Challenger - Chico
How 4311 works
A professional build workflow
Assess
Vehicle condition, owner goals, platform constraints, emissions sensitivity, and budget fit.
Authorize
Written estimate structure, repair-order scope, approvals, parts notes, and change documentation.
Build
Mechanical, swap, restoration, photo updates, quality checks, and road-ready handoff.
Restoration and restomod work is quoted through the same assess, authorize, and build path, with photo documentation handled as part of the job.
FAQ
Questions serious owners ask before they call.
Can you smog a Gen III HEMI swap in California?
Case by case. Street-legal CA work depends on year, configuration, and current rules. Flag emissions-sensitive projects on the form. Off-road / race-only builds are scoped differently.
Do I need to supply the engine and transmission?
Either works. The 60-second estimate asks whether the drivetrain is on hand or needs to be sourced.
Can I ship or trailer the car in?
Yes. 4311 takes Northern California drop-offs and national ship-in / trailer-in HEMI swap and restoration candidates.
Is the 60-second number a final quote?
No. It is a planning package total for the selected swap pieces. Final work requires shop review, written estimate, disclosures, and authorization.
How does a job start?
Assess the car and goals, authorize a written scope, then build with updates and a road-ready handoff.
Estimates and Bookings
Tell 4311 what you want built, repaired, or modernized.
This form is for major build estimates and repair bookings.
Local repair: Northern California diagnostics, drivability, and performance work.
National builds: ship-in or trailer-in HEMI swaps and documented restomods.
Written scope: Every job starts with a written scope before parts or labor are authorized.