What oil to use for a rebuilt engine?

So im getting to the stage where i am filling the car with fluids and edging ever closer to trying to starte her up after the year and a bitty restoration. The engine was fully rebuilt, bored out 1mm (due to bad scratches in the bores) and they were removed, so its got all new bearings big/small end, intermediate shaft etc, all new seals, new 10:1 compression piston heads, rings etc so my question is what is the best oil for engine burn in or for a rebuilt engine?

Also, prior to strip down an rebuild, the engine had approx 192k miles on it but I assume that makes no difference now that its been bored and rebuilt. What oils are people using for their rebuilbs, full synthetic, blend, mineral etc and what is the best one for engines that have been rebuilt with new internals etc. Thanks

If you want to switch to Synthetic now would be your time, I would do a higher than the 5w30 synth that I use in my other rides.

But 10W40 conventional is a good choice for break in

Briano1234, Yeah I was planning on getting full synthetic 10W40 but apparently there are specific break in oils also at 10W40? Not sure what the difference might be? I also read that mineral is better for breaking engine in and synthetic should not be used for break in just wondered what everyone else was doing and their thoughts on the matter.

most manufacturers are shipping new cars with synth.
And I don't think they usually have but a few miles on them when you get behind the wheel of a new car.

Older school of thought was to use a cheap mineral oil for the first 5-600 miles then change to a decent oil. It's also a thought to keep increasing the engine load for short periods over this mileage rather than granny it the whole way
I've had a few new motorcycles and the ones I was easy on during the running in used more oil than the ones I was less than careful with early on!

Jakethepeg007, yeah that's kinds of what I am leaning towards. After doing some homework yes I could put full synthetic into it but apparently that is not good for a rebuilt engine as it won't bed the rings in and it may glaze the bores. From what I have read so far a mineral oil like 10W-40 that is specifically an engine break in oil is the best bet. Apparently that is because the engine break in oil has a higher zinc content to bed the engine in. Once she's bedded in you can change to a full synthetic or use whatever oil you choose. You can also get the zinc additives for bedding in also but apparently getting a specific break in oil is the best bet/safest option. So that's what I'm moving forward with.

I would use a break in oil if you can just to be safe.