vehicle-conversions
Cost Breakdown: Upgrading Your Chevy Square Body to 400 Hp with Edelbrock Cam and Carb Package
Table of Contents
Introduction: Why 400 Horsepower for Your Square Body?
The Chevy Square Body (1973–1987 C/K Series) is one of the most iconic American trucks ever built. Whether you use it for weekend cruising, towing, or show-and-shine duty, bumping power to a reliable 400 horsepower transforms the driving experience. An Edelbrock cam and carburetor package is a proven, bolt-on path to that number, but knowing the full cost—and the supporting parts you will need—is essential before you pull the trigger. This expanded guide breaks down every major component, includes ballpark prices, and covers often-overlooked costs so you can budget accurately and avoid surprises.
Why 400 Horsepower Is a Smart Target for a Square Body
The stock small-block Chevy (SBC) in most Square Bodies made 150–200 net horsepower. A 400 hp build is roughly double that, giving you real passing power, tire-smoking torque, and an exhaust note that turns heads. It is also a realistic goal with a mild cam, a good intake, and a proper carb on a 350 or 383 stroker short-block. The 400 hp level keeps the engine streetable—good vacuum for brakes, smooth idle, and decent fuel economy—while still feeling strong on the street. Many aftermarket parts, especially from Edelbrock, are tuned for exactly this output range.
Component Deep Dive: What You Actually Need
Edelbrock Camshaft
The camshaft is the heart of the upgrade. Edelbrock offers several grind profiles that work well with their Performer line of intake manifolds and carburetors. For 400 hp on a 350, a popular choice is the Edelbrock Performer-Plus cam (#2102) or the slightly hotter #2103. The #2102 has 0.420/0.442-inch lift and 204/214 degrees duration (at 0.050), while the #2103 bumps to 0.442/0.465 lift and 214/224 duration. Both work with factory valve springs (though upgrading springs is cheap insurance).
Cost: $250–$400 depending on the specific grind and retailer. Summit Racing and Jegs often offer package deals that bundle the cam, lifters, and springs. A complete cam kit (cam, lifters, springs, retainers) can run $350–$500 and is often a better value.
Install note: You will need to degree the cam for optimal performance, or at least verify the cam timing marks. This requires a degree wheel and a dial indicator—tools that add cost if you do not own them.
Edelbrock Carburetor
For 400 hp, carburetor sizing is critical. A 600 or 650 cfm vacuum-secondary Edelbrock carb (such as the #1406 or #1405) is a perfect match for a mild 350. Too much cfm will hurt throttle response; too little will choke the top end. The Edelbrock AVS2 series with annular boosters offers even better atomization and crisp off-idle response. Expect to pay $350–$600 for a new carb; a refurbished or used unit can save $100–$150.
Tuning: Edelbrock carbs come pre-jetted for most applications, but altitude, cam timing, and exhaust changes may require a jet kit ($30–$50). Electric choke versions add around $50–$80 but improve cold starts dramatically.
Intake Manifold
A good dual-plane intake manifold is the standard for street performance. Edelbrock’s Performer EPS or Performer RPM manifolds are both excellent for 400 hp. The EPS is designed for low‑ and mid‑range torque; the RPM sacrifices a little low-end for top-end power. Both are aluminum and weigh about half of the stock cast-iron intake. Price: $200–$400. Be sure to get the correct finish: bare aluminum (cheaper) or satin/painted (slightly more). A complete gasket set (intake manifold, valve cover, and timing cover gaskets) adds roughly $30–$50.
Additional Hardware and Consumables
Do not forget the small stuff that can nickel-and-dime your budget:
- Gaskets and seals: Intake manifold gasket, valve cover gaskets, timing cover gasket, carburetor base gasket – $30–$70
- Bolts and fasteners: Intake manifold bolts (often swapped to ARP studs) – $20–$50
- Fuel line fittings: If changing carburetor, you may need a new fuel line or adapter – $15–$40
- Thermostat and housing: While the intake is off, replace the thermostat – $20–$30
- Spark plugs and wires: Upgrading ignition is wise with a hotter cam – $50–$100
- Zinc additive or break-in oil: Required for flat-tappet cams – $30–$60
All-in, plan for $150–$350 in miscellaneous parts.
Supporting Modifications (Often Overlooked)
Reaching 400 hp reliably requires a few supporting upgrades. These are not part of the “Edelbrock cam and carb package” strictly, but you should budget for them:
Exhaust System
The stock manifolds and single exhaust will strangle any performance gain. Step up to headers (long tube or shorty) and a 2.5- or 3-inch dual exhaust. Header prices range from $150–$500; a complete dual exhaust with mufflers runs $400–$800. This can double your power gain and is strongly recommended.
Ignition System
A hotter camshaft alters the cylinder pressure and requires a stronger spark. Upgrading to an HEI (High Energy Ignition) distributor (e.g., MSD or factory HEI conversion) with a quality coil and module costs $150–$300. Timing curve tuning is also important – without it, you may leave 20–30 hp on the table.
Cooling System
400 hp generates more heat. A new radiator (aluminum, ~$200–$400), a high-flow water pump ($50–$100), and a 160° or 180° thermostat are prudent investments. Overheating is the #1 killer of freshly built engines.
Fuel System
Your stock mechanical fuel pump may be adequate at 400 hp, but a high-volume pump (e.g., Edelbrock #1721, $70–$120) and a new fuel line (3/8-inch) ensure steady delivery under load. A return-style regulator is not usually needed unless you exceed 500 hp.
Labor Costs: DIY vs. Professional Installation
If you have mechanical experience and the right tools, the entire swap (cam, intake, carb, headers, ignition) can be done in a long weekend. If you pay a shop, labor rates range from $75–$150 per hour. A typical job to swap a cam and intake runs 6–10 hours; adding headers and exhaust tuning can push it to 12–16 hours. Expect $500–$1,200 for labor if you only do the top end, and $1,200–$2,000 for a full package including headers and ignition. Always get a written quote.
Total Estimated Cost Table
The following table summarizes the low-end and high-end estimates for the complete upgrade, assuming you do the labor yourself for the core package but include supporting mods.
| Component | Low Estimate | High Estimate |
|---|---|---|
| Camshaft (kit with lifters/springs) | $350 | $500 |
| Edelbrock Carburetor (600–650 cfm) | $350 | $600 |
| Intake Manifold (dual-plane) | $200 | $400 |
| Hardware, gaskets, fluids | $150 | $350 |
| Exhaust headers + dual system | $550 | $1,300 |
| Ignition upgrade (HEI distributor) | $150 | $300 |
| Cooling system (radiator + pump) | $250 | $500 |
| Fuel system (pump + lines) | $70 | $150 |
| DIY Total (no labor) | $2,070 | $4,100 |
| Labor for core package (if hired) | $600 | $1,200 |
| Grand total with labor | $2,670 | $5,300 |
Performance and Tuning Expectations
With a proper Edelbrock cam and carb package, your Square Body will idle with a distinct lope, pull hard from 2,000–5,500 rpm, and produce peak power around 5,000–5,500 rpm. Expect 0–60 mph times in the low 6-second range (depending on gearing and transmission) and a noticeable improvement in passing acceleration. Fuel economy will drop—expect 8–12 mpg on the highway—but that is the price of fun. Tuning the carburetor (idle mixture, float level, and jetting) and setting initial timing to 12–16 degrees BTDC will maximize drivability.
Dyno tuning: If you want to verify the 400 hp claim, book a dyno session ($200–$400). Edelbrock packages usually deliver on their numbers with a correct combination. For more power at higher rpm, consider switching to an RPM Air-Gap intake and a 750 cfm carb—but that pushes the budget toward $5,000 and reduces low-end torque.
Conclusion: Is the Edelbrock Package Worth It?
Upgrading your Chevy Square Body to 400 hp with an Edelbrock cam and carb package is one of the most cost-effective ways to wake up a small-block. The core components (cam, carb, intake) run about $1,000–$1,500, but realistically you should budget $2,500–$4,000 for a complete, reliable setup including exhaust, ignition, cooling, and fuel system improvements. That investment transforms a tired truck into a daily-driver that can embarrass many modern vehicles. Whether you do the work yourself or hire a shop, this upgrade offers immense satisfaction and a noticeable return in performance and street presence.
Before buying, verify your engine’s condition (compression test, oil pressure) and consider upgrading the transmission and driveline if you plan to use the power regularly. With solid planning, your Square Body will reward you with years of reliable 400 hp thrills.
For further reading, check out Edelbrock’s official site for cam and carb specifications, or browse Summit Racing for package deals. Enthusiast forums like 73-87.com offer community dyno results and real-world build threads.