Break in after LT1 piston/rod upgrade
 

Had to replace the block so I upgraded the pistons /rods bearings , used same crank and added a cam ... is there a break in process ?

We do about 150 miles then change the oil.

Billy , so technically i should not have it dynod until i break it in ? because they are obviously going to push it ??? am i seeing this wrong . Would it be better to bring it back for dyno after i break it in and change oil

Absolutely, wait until broken in to dyno. I'll go check GM's instructions that came with an LS3 crate engine I bought for a project a while back... quite conservative as I recall... and it was pulled of the Vette line at the time. with all Vette parts still attached.

Okay, got it (most are direct quotes, a few paraphrased)....

First 30 miles or one hour, varying loads and conditions No wide-open throttle or sustained high RPM accelerations.
Medium acceleration for break-in, Run 5 or 6 medium throttle to about 4000 rpms and back to idle in gear.
Hard Accelerations for break-in, Run 2 or 3 hard accelerations (WOT) to about 4000 rpms and back to idle in gear.
Change oil and filter after first 30 miles. Inspect the oil and filter.
Next 500 miles (12 -15 engine hours) normal driving conditions. Do not run at max rated speed Do not expose the engine to extended periods of high load.
Change oil and filter after 500 mile break-in period. Again, inspect the oil and filter.

Brand new motor from a shop, Id change the oil after 50, 500, 1500, 3000 mile increments, then I go normally, which will be about once a year for me but you could go by the cars OLM too. I would not use the ESP oil for the first few changes, go with a regular Delco dexos2 or just dino oil for such frequent changes.

Look for metal in the oil filter, install a magnetic drain plug or a magnet on your oil filter if you like, at every change.

Varying loads throughout the first 500 miles, change gears constantly to make the RPMs move around. You just don't want to cruise on the hwy at 1500rpm for an hour, shift it around. Never above 4000rpm until after 500. After that then drive as you normally would, if its going to blow then it'll blow.

This is what I've done on my 88 and its now at 20K on the new 398, not a problem. Saw no metal. On the GS I only did the 500 and now once a year, no metal in the oil.

Preferably dyno after the break-in, but if you have to retune then you would need to do that with a dyno unless youre fine without the WOT tune being correct. I've done it both ways and been fine.

We won't till we get at least some miles on it.