GM Squarebody Technical Directory & Semantic Sitemap
Explore every engineering solver, factory specification repository, and documentation node across the Squarebody technical hub. Designed for both human automotive restorers and autonomous search crawlers.
Core Engineering Tools & Interactive Solvers
13 Primary ToolsGM Squarebody Truck Technical Specifications Hub
Complete 1973–1987 third-generation C/K platform overview, factory engine specs, differential guide, and model year trim matrix.
Universal 1973–1987 GM Truck VIN & SPID RPO Code Decoder
Interactive 13-digit and 17-digit ISO VIN parser, SPID glove box RPO code reference, engine suffix decoder, and plant matrix.
Squarebody Transmission Specs & Drivetrain RPM Simulator
Cruising RPM calculator across TH350, TH400, 700R4, and SM465. Factory gear ratios, fluid capacities, and torque specs.
Carburetor CFM Sizing Solver & Intake Airflow Calculator
Calculate exact carburetor CFM sizing based on engine displacement (CID), operating RPM, and volumetric efficiency (VE) standards.
Squarebody Electrical Diagrams, Color Codes & Circuit Pinouts
Interactive firewall bulkhead circuit explorer, factory GM color codes, HEI ignition wiring, and dual tank switching schematics.
Small Block & Big Block Fastener Torque Specs & Sequence Pattern
Interactive 3-pass cylinder head torque sequence (1-17), main bearing cap ratings, and rod bolt specs for SBC 350 and BBC 454.
GM Squarebody Wheelbase, Bed Length & Chassis Blueprints
Factory frame dimensions, bed lengths, cab-to-axle (CA) measurements, and frame cut formulas for SWB, LWB, and Cab & Chassis models.
GM Squarebody Axle & Differential Identification Guide
10-Bolt vs 12-Bolt vs 14-Bolt identification, ring gear diameters, axle spline counts, and Eaton Gov-Lok G80 solver.
GM Squarebody Suspension Lift & Drop Geometry Guide
C10 2/4 and 4/6 drop spindle geometry, rear axle flip kit C-notch specs, K10/K20 leaf spring lift clearances, and crossover steering.
1973–1987 GM Squarebody Body Restoration & Sheet Metal Guide
Cab corners, outer/inner rockers, floor pans, yellow pine bed wood specs, and door hinge pin rebuilding procedures.
1973–1987 GM Squarebody Models & Buyer's Guide
Year-by-year styling evolution, trim hierarchies (Silverado, Cheyenne, Scottsdale), and steering box frame crack checklist.
1973–1987 GM Squarebody Engine Specs & Firing Order Guide
Bore and stroke matrix, block casting numbers (#3970010, #3999289), valve diameters, and interactive firing order animator.
1973–1987 GM Squarebody Factory Suspension Specifications
Factory OEM suspension specs, coil spring rates, rear leaf spring dimensions, sway bar diameters, and wheel alignment shims.
Factory Specifications & Verification Documents
7 DocumentsAutomotive Engineering Methodology & Verification Standards
Primary source verification protocols, GM Factory Service Manual archives (X-7832/X-8632), and mathematical derivations.
Terms of Use & Nominative Fair Use Statement
Terms of service, engineering calculation disclaimers, and nominative fair use statement for General Motors trademarks.
Security & Client-Side Isolation Standards
Zero-server computing architecture, client-side data isolation, and cryptographic edge delivery standards.
Privacy Policy & Zero-Tracking Mechanical Standards
Zero-tracking disclosure, GDPR/CCPA client-side calculation privacy declaration, and absence of third-party telemetry.
Cookie & Client-Side Storage Policy
Overview of zero-tracking client-side localStorage policies, theme preferences, and pinned specifications caching.
Terms of Service & Mechanical Disclaimers
Terms of service, engineering calculation disclaimers, and mechanical liability boundaries for shop repairs.
XML Semantic Index Sitemap
Machine-readable XML sitemap index adhering to Google Search Console and Bing Webmaster protocol standards.
Phase 2 Engineering Pipeline: Upcoming Solvers
3 Planned Modules1973–1987 Under-Dash Fuse Box Diagram & AGC Glass Fuses
Complete fuse block cavity mapping, OEM circuit ratings (3A–30A), flasher relay positions, and battery power tap terminals.
Squarebody Suspension Specs: C10 Drop Spindles & 4x4 Lift Geometry
2/4 and 4/6 drop kit alignment specs, C-notch chassis clearance, leaf spring rates, and driveshaft pinion angle tolerances.
Pollak Dual Fuel Tank Switching Valve Wiring & Selector Schematics
6-port motorized valve pinout, dash selector switch wiring, dash fuel gauge balance, and in-line fuel tank sender troubleshooting.
Platform & Powertrain Technical Coverage Index
34 Canonical EntitiesSquarebodyTech documents the full mechanical landscape of third-generation GM C/K trucks, including factory vehicle series, transmission options, engine platforms, differential hardware, and electrical circuits:
Chassis & Body Styles
- Chevrolet C10 (1/2-Ton 2WD Pickup)
- GMC K10 (1/2-Ton 4WD Pickup)
- C20 3/4-Ton (Heavy Duty 2WD Chassis)
- K20 4WD (Three-Quarter Ton 4x4)
- C30 1-Ton (One-Ton Commercial Chassis)
- K30 Dually (One-Ton Dual Rear Wheel 4WD)
- K5 Blazer (Full-Size Utility 4x4)
- GMC Jimmy (Full-Size Utility 4x4)
- Chevy Suburban (Carryall Station Wagon)
Transmissions & Overdrives
- TH350 Automatic (3-Speed Light/Medium Duty)
- TH400 Heavy Duty (3-Speed Extreme Duty)
- 700R4 Overdrive (4-Speed Automatic Overdrive)
- SM465 Granny Low (4-Speed Heavy Duty Manual)
- NV3500 5-Speed (Modern 5-Speed Manual Swap)
- NV4500 Heavy Duty (5-Speed Manual with 5.61:1 Low)
Factory Engine Families
- Small Block Chevy 350 (5.7L V8 4-Barrel)
- Big Block Chevy 454 (7.4L High Torque V8)
- 305ci V8 (5.0L Small Block V8)
- 250ci Inline-6 (4.1L Reliable Workhorse I-6)
- 6.2L Detroit Diesel (Naturally Aspirated V8 Diesel)
- Quadrajet Carburetor (4MV Spread-Bore)
- Holley Sniper EFI (Modern Throttle Body EFI)
Drivetrain, Axles & Electrical
- SPID Decal (Service Parts Identification)
- 13-Digit VIN (1973–1980 Door Pillar Format)
- 17-Digit VIN (1981–1987 Windshield ISO Format)
- G80 Gov-Lok (Mechanical Locking Differential)
- GM 10-Bolt Axle (8.5-inch Half-Ton Differential)
- GM 12-Bolt Axle (8.875-inch Performance Axle)
- GM 14-Bolt Full Floater (10.5-inch Heavy Duty Axle)
- NP203 Transfer Case (Full-Time 4WD Cast Iron Case)
- NP205 Transfer Case (Gear-Driven Part-Time 4WD Case)
- NP208 Transfer Case (Aluminum Chain-Driven 4WD Case)
- HEI Electronic Ignition (High Energy Ignition)
- Firewall Bulkhead Connector (Central Chassis Harness Pinout)
Squarebody Engineering Architecture & Technical Pipeline
Complete subsystem hierarchy modeling powertrain, drivetrain ratios, factory electrical, and Phase 2 sister tools.
Powertrain & Small/Big Block Engine Specs
CID, horsepower, compression ratios, firing order, and valvetrain tolerances for 250, 305, 350, 400, and 454.
Automatic & Manual Transmission Ratios
TH350, TH400, 700R4, and SM465 continuous highway RPM, gear ratio, and rolling tire diameter solver.
Universal 13/17-Digit VIN & SPID RPO Decoder
ISO 3779 dual-format decoder for model year, assembly plant, GVWR series, and factory options.
Factory Electrical & Bulkhead Wiring Pinouts
1973-1987 firewall bulkhead connector pinouts, GM color standards, wire gauges, and ignition circuits.