1974 D300 360 fresh rebuild will not start

The things that come to mind for me is.
Did you check the cylinder bores for taper and wear and diameter?
Did you hone the bores?
Did you gap the rings?
Did you turn the ring gaps opposite to each other?
On my first build I made that mistake I wasnt getting any cylinder pressure at all hardly and I couldn't figure out why. I had the top and the bottom ring gaps aligned. Lol we all learn from our mistakes I guess haha