Installing a Comp Cams Camshaft in Your Pontiac 455: A Complete Step-by-Step Guide with Full Cost Breakdown

Upgrading the camshaft in a Pontiac 455 is one of the most effective ways to unlock significant horsepower and torque gains. The 455 cubic-inch V8, found in full-size Pontiacs like the Grand Prix, Catalina, and Bonneville, as well as the legendary GTO and Trans Am, responds exceptionally well to a performance camshaft. Comp Cams is widely regarded as one of the top manufacturers of aftermarket camshafts, offering a range of profiles designed to optimize power delivery across the RPM band.

Whether you are building a street-driven cruiser that needs strong low-end torque or a weekend strip monster that pulls hard past 5,500 rpm, selecting the right Comp Cams camshaft and installing it correctly is critical. This guide provides a thorough, step-by-step walkthrough of the entire installation process, from initial preparation through engine reassembly and first startup. Additionally, a detailed cost breakdown helps you plan your budget with realistic pricing for all necessary components and consumables.

Tools and Materials Required

Before beginning any engine work, gather all necessary tools and replacement parts. A clean, well-organized workspace prevents lost fasteners and reduces the risk of contamination entering the engine. Below is a comprehensive list of what you will need.

New Parts and Consumables

  • Comp Cams camshaft (choose the profile that matches your performance goals)
  • Camshaft installation tool (a long bolt or a dedicated handle for sliding the cam in without damaging bearings)
  • Timing chain and gear set (double-roller chains are recommended for durability)
  • Full gasket set (intake manifold, valve cover, timing cover, and water outlet gaskets)
  • High-quality engine oil (5W-30 or 10W-40 with high zinc content for flat-tappet cam break-in; use 5W-30 or 10W-30 if using a roller cam)
  • Camshaft break-in oil additive (contains zinc and phosphorus for flat-tappet cams)
  • RTV silicone gasket maker (for timing cover and oil pan seams)
  • Coolant (50/50 mix of antifreeze and distilled water)
  • Thread-locking compound (blue Loctite for timing chain bolts and cam bolt)

Shop Tools

  • Torque wrench (½-inch drive, capable of 0–150 ft-lbs)
  • Socket and ratchet set (metric and SAE, including deep wells)
  • Allen wrenches (for some cam bolts and timing chain fasteners)
  • Screwdrivers (flathead and Phillips)
  • Pry bar (for carefully separating the timing cover)
  • Gasket scraper (plastic or brass to avoid damaging aluminum surfaces)
  • Magnetic pickup tool (for retrieving dropped bolts)
  • Oil filter wrench
  • Jack and jack stands (or a vehicle lift)
  • Shop rags and degreaser

Preparation Steps Before Removing the Camshaft

Proper preparation saves time and prevents errors during reassembly. Follow these steps methodically.

Safety and Access

  • Disconnect the negative battery cable to eliminate any risk of sparking or accidental starter engagement.
  • Raise the vehicle on jack stands or a lift to access the underside of the engine if needed. The Pontiac 455 sits relatively high in the engine bay, but access to the harmonic balancer and timing cover is easier with the car elevated.
  • Drain the engine oil and remove the oil filter. Discard the old oil properly.
  • Drain the cooling system by opening the radiator petcock and removing the lower radiator hose.

Remove Components Blocking Camshaft Access

  • Remove the intake manifold. Unbolt the carburetor or throttle body, then remove the manifold bolts in the reverse of the tightening sequence. Store the intake gaskets and manifold in a clean area.
  • Remove the valve covers. Set them aside with the gaskets.
  • Remove the rocker arms and pushrods. Label their positions if you plan to reuse them (not recommended with a new camshaft; always install new lifters and pushrods with a new flat-tappet cam).
  • Remove the harmonic balancer using a puller. Do not pry on the balancer, as it can damage the rubber bond.
  • Remove the water pump and timing cover.

Mark Timing Chain Position

Before removing the timing chain, rotate the engine by hand to bring the timing marks on the camshaft and crankshaft gears into alignment. The factory alignment has the cam gear mark at 12 o'clock and the crank gear mark at 6 o'clock, with both marks facing each other. Scribe or paint a reference mark on both gears to ensure the new cam is installed with the same orientation. This is especially important if you are retaining the original timing set and only swapping the cam.

Removing the Old Camshaft

With the timing cover and chain removed, the camshaft is exposed. Removing the old cam requires care to avoid damaging the cam bearings or the journals in the block.

  1. Remove the timing chain and gears. On most Pontiac 455 engines, the cam gear is held by a single bolt. Remove this bolt and slide the gear off the cam nose. The crank gear may need a puller if it is pressed on, but a two-piece timing set often allows the crank gear to remain in place.
  2. Unbolt the camshaft retention plate. A small plate at the front of the block holds the cam in place. Remove the two bolts and slide the plate off.
  3. Slide the camshaft out. Gently pull the camshaft straight out through the front of the block. Rotate it slightly as you pull to help the cam lobes clear the bearings. If it does not slide out easily, check for obstruction from the lifters. The lifters must be fully raised (or removed) to allow the cam lobes to pass. You may need to remove the lifter valley cover and use a magnet to lift each lifter up into its bore.
  4. Inspect the old cam and lifters. Examine the lobes for wear patterns. Uneven wear can indicate oiling issues or improper break-in. If the old cam shows signs of spalling or scoring, closely inspect the cam bearings for damage.

Important: If you are switching to a roller camshaft, you must remove the factory flat-tappet lifters and install a roller cam button and thrust plate specific to the retro-roller setup. Comp Cams provides detailed instructions with their retrofit roller cam kits.

Installing the Comp Cams Camshaft

Mounting the new cam correctly is the most critical part of the procedure. Pay close attention to lubrication and alignment.

Lubricating the Camshaft

Apply a generous coating of camshaft assembly lube (included in Comp Cams kits) to every lobe, bearing journal, and the distributor drive gear. Also, apply a thin layer of engine oil to the camshaft bearings in the block. For flat-tappet cams, the break-in additive in the assembly lube is vital for preventing lobe wear during the initial startup.

Aligning the Timing Marks

Rotate the crankshaft so that the keyway is at 12 o'clock. Align the cam gear timing mark with the crank gear mark according to the manufacturer's instructions. For a standard 0-degree installation (straight-up timing), the marks on both gears should face each other. Double-roller timing sets often have multiple keyways for advance or retard; set the cam at 0 degrees unless your cam card specifies otherwise.

Sliding the Cam into Place

  1. Attach the camshaft installation tool to the front of the cam. This tool prevents the cam from rotating and allows you to push it in without damaging the bearings.
  2. Gently slide the cam into the block, rotating it back and forth slightly to help the lobes pass the lifters. Do not force it. If resistance is met, stop and check that all lifters are fully elevated or removed.
  3. Once the cam is fully seated, the thrust plate (or retention plate) should fit flush against the front of the block. Install the two bolts and torque them to 20 ft-lbs.
  4. Install the cam gear onto the cam nose. The gear should slide on smoothly. Some Comp Cams cams use a 3-bolt pattern; others use a single ⅝-inch bolt. Apply thread locker to the bolts and torque to the spec provided with your timing set (typically 55–65 ft-lbs for the single bolt, 20 ft-lbs for the three bolts).

Timing Chain Installation

Install the timing chain over the cam and crank gears. Adjust the chain tensioner if your kit includes one. Rotate the engine by hand two full revolutions to confirm that the timing marks remain aligned. If the marks do not line up after two revolutions, the chain is installed incorrectly or one gear is off a tooth.

Reassembling the Engine

With the new cam and timing set in place, reassembly follows the reverse order of disassembly. Attention to detail here prevents oil leaks and ensures proper valvetrain geometry.

Installing New Lifters and Pushrods

Always install new lifters with a new flat-tappet camshaft. Used lifters develop a wear pattern that will not match the new cam lobes. Soak the lifters in engine oil for at least 30 minutes before installation. Dip each lifter in assembly lube and insert it into its bore. Install the pushrods and rocker arms. Adjust the rocker arm preload according to your cam card. For hydraulic flat-tappet cams, the preload is typically ½ to ¾ turn past zero lash.

Reinstalling the Timing Cover and Water Pump

  • Clean the mating surfaces of the block and timing cover thoroughly.
  • Apply a bead of RTV silicone to the timing cover gasket and the corners where the oil pan meets the block.
  • Install the timing cover and torque the bolts to 20 ft-lbs in a crisscross pattern.
  • Install the water pump with a new gasket. Use RTV on the water pump bolts to prevent coolant leaks.
  • Install the harmonic balancer. A balancer installation tool is recommended to avoid hammering on the balancer, which can damage the crankshaft thrust bearing.

Replacing the Intake Manifold and Valve Covers

  • Install new intake manifold gaskets. Apply a small amount of RTV at the four corners where the intake meets the block.
  • Lower the intake manifold into place and torque the bolts in the manufacturer's sequence to 35 ft-lbs.
  • Install the valve covers with new gaskets. Torque to 10 ft-lbs, taking care not to overtighten.

Refilling Fluids

  • Fill the engine with the specified oil and a bottle of break-in additive. Use 5W-30 or 10W-40 with high zinc content for flat-tappet cams. For roller cams, a good quality 5W-30 or 10W-30 is sufficient.
  • Install a new oil filter.
  • Fill the cooling system with a 50/50 mix of antifreeze and distilled water.
  • Reconnect the battery.

Testing and Break-In Procedure

The first startup after a camshaft installation is the most critical time for the life of the cam. A proper break-in ensures the cam lobes and lifters wear together correctly, preventing premature failure.

Priming the Oil System

Before starting the engine, prime the oil system to ensure immediate oil flow to the camshaft and lifters. Remove the distributor and use a priming tool (a long flathead screwdriver or a dedicated oil pump primer) to spin the oil pump drive shaft. Use a cordless drill at a moderate speed until oil flows from all pushrod oil holes. This takes 30 to 60 seconds. Reinstall the distributor with the rotor pointing at the #1 spark plug terminal.

Starting and Running the Engine

  1. Start the engine and immediately raise the RPM to 2,000–2,500 RPM. Do not let the engine idle at low speed for the first 20 minutes of operation. Low oil pressure and low splash lubrication at idle can cause cam lobes to scuff.
  2. Vary the RPM between 2,000 and 2,500 during the break-in period. Do not hold a steady RPM for more than 15 seconds.
  3. Monitor the oil pressure gauge. It should read at least 20 PSI at hot idle and 40–60 PSI at 2,000 RPM.
  4. Listen for any ticking, knocking, or scraping sounds. A light ticking from the valvetrain may indicate that rocker arm preload needs adjustment. A heavy knock or scraping can indicate a serious problem such as a lifter failing to rotate or a valve hitting the piston.
  5. After 20 minutes of break-in, shut off the engine and let it cool completely.

Post-Break-In Inspection

  • Check the oil for any metal particles. A small amount of fine metallic dust is normal during break-in, but larger flakes indicate wear beyond acceptable levels.
  • Re-torque the intake manifold bolts and valve cover bolts after the first heat cycle.
  • Inspect for oil leaks at the timing cover, oil pan, and valve covers.
  • Adjust the rocker arm preload again if necessary. Some lifters settle during the break-in.

Cost Breakdown for a Comp Cams Pontiac 455 Camshaft Installation

The total cost of this project varies widely depending on the specific camshaft profile, whether you choose a flat-tappet or roller setup, and the condition of your engine. Below is a realistic cost range based on current market prices from Comp Cams, Summit Racing, and other major retailers.

Mandatory Parts and Consumables

  • Comp Cams camshaft (flat-tappet): $300 – $500
  • Comp Cams camshaft (retro-roller): $600 – $1,200
  • Lifters (flat-tappet set): $100 – $200
  • Lifters (retro-roller set): $400 – $800
  • Full gasket set (Fel-Pro or similar): $80 – $150
  • Timing chain set (double-roller): $100 – $250
  • Engine oil (5 quarts): $25 – $50
  • Camshaft break-in additive: $10 – $20
  • Coolant (2 gallons): $20 – $30
  • RTV silicone and thread locker: $15 – $25

Common Optional Upgrades

  • New pushrods (hardened, cut to length): $80 – $150
  • New rocker arms (roller rockers recommended): $300 – $600
  • High-volume oil pump: $80 – $120
  • Oil pump drive shaft: $20 – $40
  • Valve springs (matched to camshaft profile): $150 – $300
  • Harmonic balancer (if original is worn): $100 – $200
  • Water pump (if original is old or leaking): $50 – $100

Total Estimated Cost

For a basic flat-tappet cam swap with no additional upgrades, expect to spend $700 to $1,200. A retro-roller cam swap, including lifters and necessary valvetrain upgrades, can range from $1,800 to $3,000. These figures assume you are performing the labor yourself. If you hire a shop, add 8–12 hours of labor at $100–$150 per hour.

Frequently Asked Questions

Can I reuse my old pushrods and rocker arms with a new Comp Cams camshaft?

It is not recommended. A new camshaft has a different lobe profile and base circle diameter, which changes the pushrod length and rocker arm geometry. Always measure for correct pushrod length and install new rocker arms if the old ones show any wear.

Do I need to degree the camshaft?

Degreeing the cam is the only way to verify that the camshaft is installed at the correct intake centerline. Comp Cams includes a cam card with every cam that specifies the recommended intake centerline. Using a degree wheel and dial indicator ensures optimal performance. It is not strictly necessary for a basic bolt-in installation, but it is highly recommended for performance builds.

What is the best Comp Cams camshaft for a street-driven Pontiac 455?

For a street cruiser with good low-end torque, the Comp Cams XE262H (flat-tappet) or XE274HR (hydraulic roller) are popular choices. For a more aggressive street/strip setup, the XE284H (flat-tappet) or XE288HR (roller) offers stronger top-end power at the expense of idle quality. Consult the Comp Cams website for detailed lobe specifications and power curves.

Final Thoughts

Installing a Comp Cams camshaft in your Pontiac 455 is a rewarding project that delivers a noticeable increase in power and driving enjoyment. The key to a successful installation lies in meticulous preparation, proper lubrication, and adherence to the break-in procedure. By following the steps outlined in this guide and budgeting for all necessary components, you can confidently upgrade your engine and enjoy the benefits of a well-matched camshaft for years to come. For additional technical support and detailed camshaft specifications, refer to the Comp Cams support page or visit a dedicated Pontiac performance forum such as Pontiac Bonneville Club for community advice.