You driving it in unmapped? Hmm little bit sketchy tbh, it's catch 22 with a rebuilt motor when it's clearly going to have pretty different fuelling and ignition requirements (different compression and different turbo you have etc) to what I presume is a base R26 map you have? Really should just wait and trailer it mapping imo.
You need to push a new engine fairly hard in terms of getting plenty of wide throttle openings to actually bed the rings in properly, so 1000+ gentle miles will do it no favours, but at the same time your fuelling and ignition needs to be spot on obviously. You can't just retard the ignition right back during this phase either as that increases egt's, and on a boosted car which will probably sit up around 800+ anyway running normally, easy to pinch a ring and crack a piston if you're lean. Equally rich is never good on fresh rings and honing either.