I own a 1971 Malibu.  It is powered by a 73 454.  The engine has been together for five years with no problems.  It has a steel crankshaft, complete Comp roller camshaft and valvetrain.  The camshaft has.612 lift.  The car had the original 273 gear in it until I broke it in April.  I found a 410 posi-traction to fit it and changed it out.  Not long after that the hot oil pressure dropped from 60 pounds down to 30 pounds.  The oil now gets jet black in just a few days of driving.  Due to the lousy gas prices, it isn't driven very often, three or four times a month at most.  I went from turning 2300 RPM to 3200 RPM at 55 MPH.  When I slow down the oil pressure comes up five or 10 pounds.  The last time I went to start the car and drive it, the oil pressure did not go over 10 pounds so I shut it right back off.  Does anyone out there have any idea what has happened?  I have been told the oil pump gears are wearing down.  I have also heard my clearances may have gotten larger since I started turning more RPM's.  A builder at the race shop that built my engine said they lost quite a few engines over the past five years because of additives being removed from the oil.(It had something to do with the catalytic converters being damaged from the un-burned blow by gases).  Anyway, they changed oil types and the problem went away.  As a side note they never did find a problem with the hard parts in any of the engines that failed due to a hard part failure.  If I remove the oil pump and replace it, do you think I will be safe or should I disassemble the entire engine and get everything cooked and cleaned and start over?  It would be nice if I could get by with just an oil pump replacement.  I am moving soon and do not have a garage at the new location. The engine has not knocked at all or made any unusual racket.  Thank you for any ideas or help..454  

It is true that oil manufacters have removed zinc additives from oil to reduce poisoning of the catalytic converter catalyst.  The lack of zinc additives has caused failures with flat tappet cam lifters (especially when breaking in a new set of lifters).  But in your case, with a roller cam, I don't think that the lack of zinc additives will cause you a problem.

Since you haven't driven it much and since you shut it down quickly when the pressure would not come up above 10 psi, I'd would assume the engine is okay and just replace the oil pump.