Passport Oil Pressure question....

VEHICLE SPECS: 1995 Honda Passport, 3.2L V6 engine. 10/30 oil, proper
levels.

Took out the Passport for a nice trip yesterday (about 250 miles round
trip). First time it's been out on the road like that since I completed my
work on it (new rocker shafts, reloaded HLA's, timing belt, new air intake,
etc.). This car has always ran rough, but the thing that really gets me
about this vehicle is that the oil pressure seems to be really low.

In the mornings, just after starting it up, oil pressure is about 50-55.
When the car idles down, it gets to about 30. When driving just the six
miles to town and back, it stays between 15-30 depending on speed. It stays
at about 30 at 2000 rpm. Sometimes when driving and at a light, it gets as
low as 800RPM with almost 0 oil pressure.

Book says oil pressure at 500rpm should be 10. At 2000RPM, 30-55. This car
has never gotten to 55 at 2000RPM, but stays at about just under 30 or just
above 30.

What's the best way at this point to diagnose whether the oil pump needs
replacement or is working fine?

Owners of Rodeos and Passports? Is your oil pressure running as mine is; so
is this normal. Just seems to me that it's lower than it should be.

Another thing: With the installation of this new air intake, I have enjoyed
better travel. However, it seems as though it takes more effort for the car
to get that better travel. Even up little hills which my 4cyl. Saturn
handles with no problem, this V6 is struggling, even upshifting constantly
to achieve travel over. I am going to retinstall the factory air intake to
see if this makes any difference. Maybe the oil pressure problem is causing
the troubles.

Thanks for any comments/advice.

AJPDLA