Now that the engine is off to be rebuilt, I need to ensure everything is on hand for a successful break-in. Please pitch in! I'll edit and correct the post as errors are found.

1) oil for break in
- SAE 30 weight for the first start with a fresh filter to allow any debris settle to the bottom of the pan. Here's some amsoil, do I need any additional addives?
http://www.amsoil.com/shop/by-product/motor-oil/gasoline/break-in-oil-(sae-30)/?code=BRKQT-EA

2) prime the engine, spin until at a minimum the oil starts coming out the rockers. Prime three more times with a 1/4 turn crankshaft rotate crankshaft 1/4 turn.
- If automatic transmission and new fluid, pour in 5 quarts.

3) break-in: 20 minutes at 2,000 RPM. re-adjust the valves, run another 20 minutes around the neighborhood varying the RPM, but not letting it idle much.
- once car starts, pour in 4 additional quarts after start, check fluid level and add more until full. Once fluid is full, with foot on the brake, run through all the gears.

4) New oil & filter. Use break-in oil again? Amsoil site skips the second oil change saying only to run the car less than 1,000 miles before changing oil again.

5) Run another 500 miles. Change oil and filter.
- vary driving RPMs up and down, don't do long sustained highway runs nor let it idle a bunch.

Note: the only item I'd add here is 2 bottles of GM Engine oil supplement per oil fill - why 2 - to get extra zinc content.

Recommended GM Crate Engine Start-Up Procedure

1) Safety first !!! If the car is on the ground, be sure the emergency brake is set, the wheels are chocked, and the transmission cannot fall into gear.

2) Be sure to check the oil 10w30 (non-synthetic) (GM#12368084, see bottom of page)level in the engine, remove the distributor,install an oil pressure gage and prime the engine using a 1/2" drill motor. Have an assistant rotate the engine 4 complete turns of the crankshaft while running the oil pump to ensure the oil reached all the rod bearings. Reinstall the distributor and verify your installation work.

3) Run the engine between 2,000 and 2,500 RPM, with no-load on the engine for the first 30 minutes.

4) Adjust the distributor timing roughly by hand for a quick start up and smoothest idle possible.

5) Adjust the carburetor settings, if necessary.

6) After the first 30 minutes of the engine running, set the ignition timing to proper timing specifications.

7) Drive the vehicle with varying speeds and load on the engine for the first 30 miles. Be sure not to use a lot of throttle or high RPM !!!

8) Run five or six medium-throttle accelerations to about 5,000 RPM (55 or 60 MPH), then let off in gear and coasting back down to 20 MPH.

9) Run a couple hard-throttle accelerations to about 5,000 RPM (55 or 60 MPH), then let off in gear and coasting back down to 20 MPH.

10) Change the oil and filter with 10W30SG oil and PF1218 AC Delco oil filter GM#25160561.

11) Drive the next 500 miles normally, without high RPM's (below 5,000 RPM), hard use, or extended periods of high loading.

12) Change the oil and filter again.

13) Your engine is now ready for many happy cruising miles !!!
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Vary the RPM slightly.

If you can get to a freeway that would be an optimum place. Drive at 2000-2500 for awhile and let everything seat...this would be after the cam break in...and that would also help you get the engine tuned up as well as break the tranny in. For the 1st 500 miles you'll be breaking the engine and tranny in. Easy driving at consistent RPMs with minimal lugging or high reving. Some say that getting on it once in awhile to put the engine under a good load helps to seat the rings.

I will give you my two cents here. I just successfully broke in a heavily modified 261 motor, relatively heavy valve springs, heavy GMC rods and forged pistons, modified rod bearings, solid cam, old fashioned chrome rings (hey, I had them in my parts stash so I used them, lol). I used Brad Penn 30 wt break in oil. High Zinc package, excellent cold cling to the parts. Motor broke in perfectly with no issues. Fired it up, varied 2000 to 2500 rpm for 25 minutes. Cooled it down, reset valves, fired back up, run it for another 15 minutes. Let it cool down. Drove it around, not to heavy handed for the first 40 miles, little heaver handed the next 15 (which is all I have on it at the moment). No issues whatsoever.

good plan