Your oil is thicker on start up when it is cool and therefore will create more pressure when it flows. As the oil heats up it gets thinner and produces less pressure. That doesnt mean that you have an internal engine problem and it doesnt mean that you dont.
The first thing to try is to do an oil change and use a heavier weight oil than you have been using or using the same oil but with an additive like Lucas Oil. If this improves or corrects your problem then...you can either just continue running the heavier oil, replace the oil pump with a higher volume pump...or go looking for clogged oil passages in the motor that are retricting flow...which really shouldnt be necessary to do at 62,000 miles.
Chevy Mechanic
20 years experience