Good job checking all the clearances - many builders don't do this, and it's a great last check during assembly to make sure everything worked out. If you've got a mic and bore gauge, great - but if not Plastigage is still a pretty decent way to double, double check.
I personally prefer using a good assembly lube vs. oil - for years I used a 50/50 mix of 30 wt dino oil and GM EOS...but I've been using
Lubriplate 105 assembly lube for a long time and recommend it highly. I generally coat everything with this, and put a pretty healthy slather on the pistons especially as they'll undergo a lot of wear during the short break-in. If you oiled the cylinder bores and all the bearings you're OK...but certainly make sure you preoil the engine before start, rotating the engine a couple of times to make sure they're darn wet and have oil pressure immediately available.
On the cam lobes and lifter bases, you need a high-pressure cam lube that may have come with the cam; this is
critical if you expect the cam to survive break-in.
I also add a pint of GM EOS for break-in, and with the first 3 oil changes. There are other break-in additives and oils as well from CompCams and others.
Just a note for future builds - the bores come back from the shop with quite a bit of grit embedded in the cylinder walls from the honing process. My approach is to pass paper shop towels coated with WD-40 through the bores until they come out clean. Not doing this can lead to poor cylinder seal...although with modern moly rings it's a lot less likely.