1998–2002 F-body LS1 cam and valve spring swap, step by step

1. Front on ramps or jack stands. Pull the strut tower brace if you have one.
2. Disconnect the negative battery cable. Write down the radio code first if your radio has one.
3. With the engine cold, open the radiator cap and drain the radiator from the petcock at the bottom passenger side.

1. Unplug the air temperature and MAF sensors and remove the lid, MAF and intake tube as one piece.
2. Remove the radiator support tray (four 10 mm bolts).
3. Unbolt the two AIR pipes from the manifolds or headers (two bolts each). Plan on new gaskets.

1. Pull the plug wires by the boots, not the wire, and unplug the coil harness.
2. 1998 cars have each coil bolted to the valve cover; 1999–2002 cars have the coils on a bracket that comes off as one piece.
3. Disconnect the PCV hoses at the valve covers and remove both covers.

1. Remove the 16 rocker bolts (8 mm), the rockers, the pushrods and the rocker pedestals.
2. Keep every part in order so each goes back where it came from.

1. Release the belt tensioner (15 mm) and remove the belt.
2. Disconnect the water pump hoses and remove the pump (six bolts).
3. Unplug the fans, free the A/C condenser from the radiator tabs and lift the radiator and fans out together. The condenser stays in the car with its lines connected. Cover the battery terminals.

1. Lock the crank: manual cars in gear with the parking brake set; automatics, remove the starter and lock the flexplate.
2. Break the balancer bolt loose (24 mm socket, long breaker bar).
3. Pull the balancer with a puller that pushes on a protector or a longer bolt in the crank, never on the crank threads themselves.

Careful: Pulling against a short bolt or bare threads can strip the crankshaft threads, which makes the next step a nightmare.

1. Remove the timing cover bolts and the cover.
2. Stuff a clean rag in the front of the oil pan so nothing falls in.

1. Turn the crank until the crank gear dot points straight up and the cam gear dot points straight down (dot to dot).
2. Remove the three cam gear bolts and take off the gear with the chain.

1. Spin the cam a few turns to push the lifters up into their guides.
2. Hold them there with a lifter holding tool, or with 16 retractable pen magnets down the pushrod holes, clipped to the head.
3. Spin the cam again: if any magnet moves, that lifter is too low. Reset it.

Careful: Don't trust friction alone. A lifter that drops behind the cam means pulling the heads to fix it.

1. Remove the cam retainer plate (four bolts).
2. Thread two long bolts into the cam nose as a handle and slide the cam out slowly, turning it as you go so the lobes don't nick the cam bearings.
3. Support the cam with both hands once it is partly out. Lift or lower the A/C condenser just enough to clear it, without kinking the lines.

1. Remove the spark plugs.
2. Either fill the cylinder with shop air through a spark plug adapter, or bring that piston to top dead center so the valve can't fall far.
3. Working by top dead center: with the timing dots lined up, cylinders 1 and 6 are at the top. Turn the crank 90° for 8 and 5, another 90° for 7 and 4, and another 90° for 2 and 3 (firing order 1-8-7-2-6-5-4-3).

Careful: With air in a cylinder, that piston must be at top dead center or the air pressure will turn the engine.

1. Compress the spring with an on-head compressor. If the retainer sticks to the valve, a light tap on the retainer frees the locks.
2. Lift out the two locks with a magnet, release the compressor, and remove the retainer and spring.

1. On 2001–2002 heads the valve seal and spring seat are one piece. On 1997–2000 heads the seal is separate and comes off before the seat.
2. Intake and exhaust seals are different. Oil the valve stem and tap the new seal on squarely with a deep socket.

1. Set the new spring and retainer on the seat and compress it, keeping the retainer centered on the stem.
2. Install both locks (a dab of grease holds them), release slowly and make sure they sit in the groove. Wear safety glasses.
3. Check installed height if the spring maker gives one. Repeat for all 16.

1. Coat the lobes and journals with fresh oil or the cam maker's lube.
2. Slide it in slowly with the same two-bolt handle, supporting it the whole way.
3. Install the retainer plate with medium-strength thread locker.

Torque: cam retainer plate 18 ft-lb

1. Replace the chain on a high-mileage engine or with a big cam.
2. If the oil pump comes off: new pickup O-ring, slide the pickup in centered, center the pump on the crank before tightening.

Torque: oil pump 18 ft-lb, pickup bolt 106 in-lb

Careful: A pinched pickup O-ring means low oil pressure and tearing it all back down. Go slow here.

1. Crank dot straight up, cam dot straight down, chain on both gears. Seat the gear on the cam dowel.
2. Install the cam gear bolts with thread locker.
3. Turn the crank two full turns by hand and check that the dots line up again. Degree the cam if you want to confirm its install point.

Torque: cam gear bolts 26 ft-lb

Careful: One tooth off can put valves into pistons. Check twice.

1. Check pushrod length with a checker if the heads were milled or the cam has a smaller base circle. 7.400 in. is stock.
2. Install pushrods, pedestals and rockers. Turn the crank so each lifter is on the base circle before torquing its rocker.
3. Turn the engine two full turns by hand. If it binds, stop and find out why (timing or piston-to-valve clearance).

Torque: rocker bolts 22 ft-lb

1. Drive the old seal out and press in a new one.
2. New gasket, a dab of RTV where the cover meets the oil pan, bolts snug only.
3. Center the cover on the crank (alignment tool or the balancer), then torque the bolts.

Torque: front cover 18 ft-lb

1. Press the balancer fully on with an installer tool, or with the old bolt to 240 ft-lb. Remove the old bolt.
2. Install a new bolt: 37 ft-lb, then a further 140° with an angle gauge.

Torque: balancer procedure

Careful: Don't stop short of the full angle or skip the seating pass. A balancer that isn't fully seated or clamped can walk off the crank.

1. Water pump with new gaskets (two passes), belt, radiator and fans, hoses.
2. Valve covers, coils, plug wires, spark plugs (start by hand), AIR pipes with new gaskets, intake.

Torque: water pump 11 then 22 ft-lb · spark plugs · valve covers 106 in-lb · AIR pipes 15 ft-lb

1. Fill with Dex-Cool and bleed the air out of the cooling system.
2. Fresh oil and filter; check the level.

1. Leave the coil harnesses unplugged and crank in short bursts until you see oil pressure. Listen for anything hitting.
2. Plug in the coils and start it. Expect lifter noise for a few seconds.

Careful: If oil pressure doesn't come up within a few seconds, shut it off and find out why.

1. Check for leaks, bring it to temperature and top off the coolant as air bleeds out.
2. Drive it gently the first day. Stiff performance springs don't like high rpm cold: always warm the engine before going to redline.

1. A cam changes idle airflow, fueling and spark. Build the start-up tune with the turn-on tune sheet and the cam tuning guide.
2. Fix idle with airflow and spark in the tune. Drilling the throttle blade is an old workaround; tuning does it properly.
3. Log fuel trims and knock, then finish on a dyno before any hard pulls.