Every kit on this page ships with its free build guide already paired.
1,840 hand-written guides across 312 vehicle platforms. Each one pre-bagged with the right parts, the right torque specs and a printed wiring schematic — so you stop chasing four forums, three retailers and a YouTube tab just to swap a starter.
- 1,840free guides live
- 312vehicle platforms
- 14ASE-certified techs
No skim. The guide + wiring diagram downloads free — the kit ships when you're ready to wrench.
Browse by system, platform and skill level — every kit pre-paired with its free guide.
Six working categories, 312 vehicle platforms. Pick the system, pick the build, the guide is already loaded for you the moment the box lands.
Showing 214 of 1,840 kits. Use the filters above to narrow the catalog — the guide for every visible kit is free to download.
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01 / 06
Engine & Drivetrain
Starter swaps, alternator upgrades, clutch kits, LS swap coolant kits, transmission mounts. 612 kits live — most-written category on the site.
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02 / 06
Brakes
Drum-to-disc conversion kits, big-brake upgrades, pad & rotor refresh bundles, master cylinder swaps, E-brake cable kits.
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03 / 06
Suspension
Lift kits, lowering springs, control arm refresh, ball joint & tie-rod bundles, sway-bar upgrades, coilover conversions.
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04 / 06
Electrical & Wiring
Dual-battery wiring harnesses, headlight relay upgrades, fuel-pump rewires, trailer plug kits, chassis grounds. Drawn from OEM service manuals — not crowd-submitted.
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05 / 06
Interior & Restoration
Headliner replacement bundles, seat hardware kits, dash pad restoration, carpet sets with correct fasteners, window regulator repairs.
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06 / 06
Off-Road & Overland
Winch mounts, recovery points, dual-battery trays, auxiliary lighting harnesses, fridge & compressor wiring — all paired with overland-specific guides that pass Colorado high-alpine testing.
Showing the six featured categories. The full catalog has 1,840 kits — apply the filters above or browse all systems.
See all 1,840 kitsVerified scale, verified accuracy.
- 1,840+ free build guides live on the site
- 312 vehicle platforms covered, 1965–2024
- 94.7% kit-fitment accuracy, free replacement on the rest
- $186 average shopper savings vs. sourcing individually
From 218,000+ kits shipped since 2019 · internal survey of 4,118 DIYers, Dec 2024
Three builds picked straight from this week's catalog.
See the exact platform, the exact kit and the exact guide before you filter further. Each card links to the live kit page and a free guide download.
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Muscle · Restoration
BUILD №04811965–73 Mustang drum-to-disc brake conversion
A complete front disc-brake kit for early Mustangs — loaded calipers, vented rotors, braided stainless lines, master cylinder, and proportioning valve — bagged in build-order so the guide is the only paper on the bench.
- Platform
- 1965–73 Ford Mustang
- System
- Brakes
- Difficulty
- Intermediate · 4.2 hrs
- Fitment
- 100% verified on 11 sub-models
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Off-Road · Electrical
BUILD №12142016–23 Tacoma dual-battery wiring harness
Everything to add a second battery for a fridge, lighting or winch without backfeeding — pre-cut wire, labeled relays, in-line fuses, and an OEM-sourced schematic drawn in-house (not crowd-submitted). QR code on the bag pulls schematic revisions free for life.
- Platform
- 2016–23 Toyota Tacoma
- System
- Electrical & Wiring
- Difficulty
- Intermediate · 5.6 hrs
- Schematic
- In-house, drawn from OEM manual
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Daily · LS Swap
BUILD №15022007–13 Silverado LS swap coolant kit
Molded coolant hoses, stainless T-fittings, thermostat housing and reservoir lines — every hose cut and labeled so the builder never walks to a parts counter mid-install. Paired with our 78-page LS swap guide written by the in-house ASE team.
- Platform
- 2007–13 Chevy Silverado
- System
- Engine & Drivetrain
- Difficulty
- Advanced · 11.4 hrs
- Guide length
- 78 pages, peer-reviewed
Every kit ships with a written guarantee — and a QR code that pulls free schematic updates for the life of the build.
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94.7% fitment accuracy
Every part in every kit is verified against the platform's VIN, sub-model and trim before it ships.
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Free replacement guarantee
If any part in any kit doesn't fit, we ship the correct piece free — you keep the original.
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Lifetime free revisions
QR code on the bag pulls the latest schematic and torque-spec updates for that build — forever.
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4.86 / 5 post-install rating
Across 218,000+ kits shipped since 2019 — pulled from verified buyer reviews on each kit page.
Drawing the diagrams, packing the kits — in-house, not crowd-sourced.
Every guide on FreeCarKits is authored by our 14-person in-house team of ASE-certified technicians in Boulder, Colorado — specialists averaging 11 years of experience who sign their work on the cover page. Our team includes former dealership service managers and master techs who started this company in 2019 after watching too many DIYers ship a wrong part from a forum thread.
Wiring diagrams on the site are drawn directly from OEM service manuals — not crowd-submitted and not lifted from forums. That in-house discipline is what lets us back the catalog with a 94.7% fitment accuracy rate and a free replacement guarantee on the rest. The same discipline is why the catalog covers 89% of the top-50 best-selling US-market vehicles with verified OEM-sourced schematics — and why a kit average shopper saves $186 per project versus sourcing parts individually from the nine major parts retailers we track.
The catalog you scrolled past is the result: 1,840 free build guides, 312 vehicle platforms, and 218,000+ kits shipped with a 4.86/5 average post-install rating. Named Best Free DIY Auto Resource 2024 by AutoWeek Gear Guide (April 2024, p. 62), and cited by Grassroots Motorsports, Hot Rod and The Drive in 2024. Now part of a 412,000-strong community of registered DIYers — and growing.
Safety note: FreeCarKits guides are written for experienced DIYers. For brake, fuel-system, airbag or any high-voltage EV work, always consult a licensed mechanic before you touch the system.