are you running stock ECUs? plan on getting a tune?
stock camshafts? stock pistons/compression?
Personally, I would let engine builder start up first time. Could pressure feed oil, start it up and run for 10-20mins to bed cams in (if new). From then, you know it runs, doesnt leak any fluids and won't go clunk 200m down the road. From there, its up to you how you run everything in.