I recently rebuild my 22re. I am running 5w30 with lucas break in oil additive.I am up to about 400 450 miles on it since rebuild. We have been getting hammered by snow up here in nor cal. I have just been driving it around town since I got it going. I was considering doing an oil change and heading up for a snow run!?!?!?!?

 

you should be fine, but it won't be fully broken in until around 5000 miles.

once my rebuilt 22R hit about 6000 miles it REALLY woke up.

you should be fine though, just take it easy and watch your oil pressure..

 

Don't drive it any differently than you would with it had 100k on it.

 

What did the engine builder tell you to do? What does his warranty cover? I know on my 3.0, they had me change the oil at 300, then at 1500, then at 3000. First oil change looked like JB weld pouring from my pan. I'd start with the engine break-in that they suggest. But, it's your engine.