New to me Barracuda with Mopar Crate 390hp low oil pressure

Shop tested the alternator and it showed low amps at idle. With the electric fuel pump and electric fan is pulling more than the little alternator puts out at 900rpm.
Most likely will get a 160amp one wire conversion.
Roger. One thing I have become aware of is that 1 wire alternators can fail to self-excite and won't put out current if they sit for many months. It is not all of them; just the few that lose adequate residual magnetism in the rotor core when sitting for a long time.