Carnut427,
I understand the SO427 FE came with a HV FORD NASCAR pump, but very very few 390's did, unless you are including the RACING 390's such as the 401HP etc. Hopefully they are in their original cars and properly restored.
Have never seen a stock Chevy with a High vol/press pump from the factory unless it was a "crate engine", engine in white for NASCAR machining, or one of the Chevy Racing applications, one very similar to the street engines in any of the 60's manufacturer's.
MaSnaka,
The base 390 and the base
oil pump should be fine, I would not pressure up with the spring method, UNLESS you are upgrading the seals, gaskets, chamfering the crank, block ports, rodding out passages, etc. Doing just that you are not changing the volume of
oil to the crank to barely over 10% of stock with "just spring" method, but however, will fill the lifter gallery with the difference. By "orficing" the
oil passages, you can push more oil to the crank if the engine is going in the the 5000 rpm plus region a lot. With that you need a FE person to do the machining and fit up, not "just a engine re-builder".
Good Luck
grumpy