Suspension Brands and Upgrades - Square Body Trucks

Overview

The suspension system on 1973-1987 GM Square Body trucks (C10, C20, K10, K20, K5 Blazer, and Suburban) is critical for ride quality, handling, and load-carrying capability. After 35+ years, most original suspension components are worn and require replacement or upgrading. This comprehensive guide covers the major suspension brands available for Square Body trucks, from budget-friendly OEM replacements to high-performance aftermarket systems.

Square Body trucks used different suspension configurations depending on model year and application. Understanding these differences and the available brand options will help you choose the right components for your restoration, daily driver, or performance build.

Common Issues

Square Body suspension systems commonly experience these problems:

• Worn leaf springs - Sagging, broken leaves, or complete failure
• Deteriorated shock absorbers - Oil leaks, reduced dampening, blown seals
• Bushings failure - Cracked or missing rubber bushings in leaf spring eyes and shackles
• Ball joint wear - Excessive play in upper and lower ball joints (4WD models)
• Control arm bushings - Deteriorated rubber bushings causing alignment issues
• Steering component wear - Tie rod ends, idler arms, and pitman arms with excessive play
• Torsion bar fatigue - Reduced ride height and poor handling (4WD models)

Parts & Materials Needed

Popular Suspension Brands by Category

OEM Replacement Brands

• ACDelco - GM's OEM parts division
• Part numbers retain original GM specifications
• Best for stock restoration builds

• Available through GM dealers and major suppliers

• Moog - Premium OEM replacement

• Known for ball joints and steering components
• "Problem Solver" series addresses common wear issues

• Lifetime warranty on many components

• Monroe - OEM shock absorber supplier

• OESpectrum series for stock replacement
• Reflex series for improved performance

Performance Upgrade Brands

• Belltech - Lowering specialist
• Complete lowering kits (2"/4", 3"/5", 4"/6" drops)
• Part numbers: 691ND (2"/4" kit), 692ND (3"/5" kit)

• Includes springs, shocks, and hardware

• McGaughy's Suspension - Comprehensive lowering solutions

• Budget-friendly lowering kits
• Complete 7" drop kits available

• Part numbers: 33157 (4"/6" kit), 33158 (4"/7" kit)

• Ridetech - Air suspension systems

• Complete air ride systems
• Coilover conversions for front and rear

• Part numbers: 11230298 (front coilover system)

• QA1 - Performance suspension

• Adjustable coilovers and shocks
• Precision Series for street/strip applications
• Part numbers: DK11-C10F (front coilover kit)

Off-Road/Heavy Duty Brands

• Rough Country - Budget off-road upgrades
• Lift kits from 2" to 6"
• Complete suspension systems

• Part numbers: 260.20 (2" lift kit)

• Skyjacker - Heavy-duty off-road

• Hydro and Nitro shock series
• Complete lift systems

• Rock Ready series for extreme applications

• Rancho - Premium off-road

• RS5000X and RS9000XL shock series
• Adjustable dampening options
• Part numbers: RS5000X series

Step-by-Step Brand Selection Guide

Step 1: Determine Your Application

1. Stock Restoration - Choose ACDelco or Moog OEM replacement
2. Street Performance - Consider Belltech or McGaughy's lowering
3. Off-Road Use - Select Rough Country, Skyjacker, or Rancho
4. Show Quality - Ridetech or QA1 premium systems

Step 2: Identify Your Truck Configuration

• 2WD (C-series) - Front A-arms, rear leaf springs
• 4WD (K-series) - Front torsion bars, rear leaf springs
• Heavy Duty (20-series) - Larger components, higher capacity

Step 3: Budget Considerations

• Budget ($500-1000) - Monroe, Gabriel, or basic McGaughy's
• Mid-range ($1000-2500) - Belltech, Moog, or Rough Country
• Premium ($2500+) - Ridetech, QA1, or Rancho systems

Step 4: Order Complete Systems

Most brands offer complete kits including:
- Front and rear springs/coilovers
- Shock absorbers
- Necessary hardware and brackets
- Installation instructions

Year/Model Differences

1973-1980 vs 1981-1987 Differences

• Shock mounting - Earlier trucks use different shock mount configurations
• Spring rates - Later trucks often have lighter spring rates
• Parts availability - 1981-1987 parts more readily available

Model-Specific Considerations

C10/K10 (1/2-ton)

• Most aftermarket support
• Widest brand selection available
• Standard 5-lug wheel pattern

C20/K20 (3/4-ton)

• Limited lowering options due to heavy-duty use
• Focus on Moog, Monroe, or Rancho brands
• 8-lug wheel pattern affects some suspension choices

K5 Blazer/Suburban

• Shorter wheelbase affects spring rates
• Some brand kits require specific part numbers
• Consider load capacity for Suburban applications

2WD vs 4WD Specific Brands

2WD (C-series) Recommendations

• Belltech - Excellent lowering options
• McGaughy's - Budget-friendly complete kits
• Ridetech - Premium air ride systems

4WD (K-series) Recommendations

• Rough Country - Comprehensive lift options
• Skyjacker - Heavy-duty off-road focus
• Rancho - Premium adjustable systems

Tips & Best Practices

Brand Selection Tips

• Research warranty policies - Moog offers lifetime warranties on many parts
• Consider complete systems - Mixing brands can cause compatibility issues
• Check local dealer support - Some brands have better local parts availability
• Read user reviews - Square Body forums provide real-world feedback

Installation Considerations

• Use brand-specific hardware - Don't mix hardware between manufacturers
• Follow torque specifications - Each brand provides specific torque values
• Consider professional installation - Complex systems like air ride require expertise

Common Mistakes to Avoid

• Mixing spring rates - Don't combine different brand springs front/rear
• Ignoring load requirements - Choose appropriate capacity for your use
• Skipping alignment - Always align after suspension changes
• Cheap shock absorbers - Poor shocks ruin good spring performance

Troubleshooting

Brand-Specific Issues

Belltech Systems

• Problem: Harsh ride quality
• Solution: Verify correct spring rates for vehicle weight
• Check: Part numbers match your specific year/model

McGaughy's Kits

• Problem: Uneven ride height
• Solution: Ensure all components from same kit revision
• Check: Proper installation of included spacers

Ridetech Air Systems

• Problem: Air leaks or uneven height
• Solution: Check all fittings and air lines
• Check: Proper controller calibration

Rough Country Lifts

• Problem: Excessive bounce or poor handling
• Solution: Verify shock valving matches lift height
• Check: All components properly torqued

General Brand Troubleshooting

• Verify part numbers - Ensure components match your specific application
• Check installation - Review brand-specific installation instructions
• Contact technical support - Most major brands offer technical assistance
• Consider professional diagnosis - Alignment shops can identify installation issues

Warranty Claims

• Keep receipts - Required for all warranty claims
• Document issues - Photos help with warranty submissions
• Contact manufacturer first - Don't return to retailer without authorization
• Follow procedures - Each brand has specific warranty claim processes