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I will be installing a new GM crate engine this week and they don't say anything specifically as for cam break in. This is the document they have available to download at Pace

Quote:

Start-up and Break-in Procedures:
1. After installing the engine, ensure the crankcase has been filled with 10w30 motor oil (non-synthetic) to
the recommended oil fill level on the dipstick. Also check and fill as required any other necessary
fluids such as coolant, power steering fluid, etc.
2. The engine should be primed with oil prior to starting. Follow the instructions enclosed with the tool. To
prime the engine, first remove the distributor to allow access to the oil pump drive shaft. Note the
position of the distributor before removal. Install the oil priming tool. Using a 1/2" dill motor, rotate the
engine oil priming tool clockwise for three minutes. While you are priming the engine, have someone
else rotate the crankshaft clockwise to supply oil throughout the engine and to all the bearing
surfaces before the engine is initially started. This is the sure way to get oil to the bearings before you
start the engine for the first time. Also, prime the engine if it sits for extended periods of time. Reinstall
the distributor in the same orientation as it was removed. After the engine has been installed in the
vehicle, recheck the oil level and add oil as required. It is also good practice to always recheck the
ignition timing after removal and reinstallation of the distributor. See step 4 or engine specifications
for the proper timing information.
3. Safety first. If the vehicle is on the ground, be sure the emergency brake is set, the wheels are chocked
and the car cannot fall into gear. Verify everything is installed properly and nothing was missed.
4. Set initial spark timing at 10o before top dead center (BTDC) at 650 rpm with the vacuum advance line
to the distributor disconnected and plugged. This setting will produce 32o of total advance at wide-
open throttle (WOT). The HEI vacuum advance canister should remain disconnected. This engine is
designed to operate using only the internal centrifugal advance to achieve the correct timing curve.
Rotate the distributor counterclockwise to advance the timing. Rotate the distributor clockwise to
retard the timing.
5. When possible, you should always allow the engine to warm up prior to driving. It is a good practice to
allow the oil sump and water temperature to reach 180°F before towing heavy loads or performing
hard acceleration runs.
6. Once the engine is warm, set the total advance timing to 32° at 3000 RPM.
7. The engine should be driven at varying loads and conditions for the first 30 miles or one hour without
wide open throttle (WOT) or sustained high RPM accelerations.
8. Run five or six medium throttle (50%) accelerations to about 3000 RPM and back to idle (0% throttle) in
gear.
9. Run two or three hard throttle (WOT 100%) accelerations to about 3000 RPM and back to idle (0%
throttle) in gear.
10. Change the oil and filter. Replace with 10w30 motor oil (non synthetic) and a PF454 or PF1218 AC
Delco oil filter. Inspect the oil and the oil filter for any foreign particles to ensure that the engine is
functioning properly.
11. Drive the next 500 miles under normal conditions or 12 to 15 engine hours. Do not run the engine at
its maximum rated engine speed. Also, do not expose the engine to extended periods of high load.
12. Change the oil and filter. Again, inspect the oil and oil filter for any foreign particles to ensure that the
engine is functioning properly.
13. Do not use synthetic oil for break-in. It would be suitable to use synthetic motor oil after the second
recommended oil change and mileage accumulation. In colder regions, a lower viscosity oil may be
required for better flow characteristics.

Nothing about 2000 RPMs for 20 minutes. So, are the new GM engines ok to not go through the usual cam break in ?