1968 340 oil capacity

Because you have a 340,
in the which it is normal for them to BURN 1 USqt every 900 miles even when brand new; I highly recommend an extra capacity oil pan, in the which you can put at least 2 extra quarts without it getting into the windage tray under your driving style. Like said, the two most important things are;
1) to keep the pick-up covered, and
2) to keep the oil off the crank.
If you got that handled, then, where the oil is on the dipstick is a whole bunch less important.