A 0.040" overbored 460 is a 0.040" overbored 460. It displaces 468 cubic inches, but please don't refer to your engine as a "Ford 468" because that is not what really it is. It is a 460 that has simply been bored 0.040" over, technically speaking.
The crankshaft gear marking that you choose to use should be in the 12 o'clock position, and the cam gear dot should be in the 6 o'clock position. The "0" is supposed to mean that the cam phasing is neither advanced nor is it retarded, but the cheapo timing sets can have their lower gear's keyway broached just about anywhere and so in most performance builds it is wise to degree the camshaft. In a stock rebuilder, it's probably no big deal and you'll be fine. On the other hand, the aftermaket timing sets with three keyways to choose from (on the crank's gear) can be broached to the 1968-1971 timing set specifications or for the 1972 & up timing set specifications. If you have a 1972 & up timing set then you should advance the camshaft 4 degrees (8 crankshaaft degrees). How can you tell which chain set you have? You need to degree your cam timing.
No, having the cam timing here or there (relative to which chain you used) will not cause you to have 0-30 psi cylinder presusre. Perhaps your valves are stuck from the rain and moisture...or you honed and ringed incorrectly...or something else altogether.