I assume you initially may have chosen the high volume pump because of the
possibility of "oil starvation" to the back of the engine under a severe
load(?).  I have read of the exposure in the ford 335 series v8's and have
studied some mods that run an additional oil supply line outside the engine to
the back of the block or something like that, I think it was discovered by dirt
track racers using the engine hard.  I am currently building a 400 for a '79
f-250 that is still in parts but will be assembled in 2-3 weeks so any
additional detail of your oiling issue with the engine you could share would be
greatly appreciated.  Like if all the rest of the oiling system was stock or had
mods been put on, did you have any problem with the distributor gear
stripping-prematurely wearing out due the extra pressure from the higher volume
pump, etc, etc.

Since this is OT, it would probably be appropriate to communicate via email only
from now on in this thread.  Thanks in advance for any info you can add.  
regards, Joe.

I generally lurk and do not post in the Dodge group but,
since you brought up the Ford 351 engine with which I have
at least a passing interest and knowledge of, I will take a
shot at getting flamed here.

Your problem was not the HV pump.  It was a bad rear seal
which was probably a result of excessive wear of the rear
main which, in turn, was probably a result of the inadequate
oiling of the rear main in the 335 series Ford engines.  I
have seen this a number of times during overhaul.

A high volume pump at proper stock pressure setting will do
absolutely nothing in an engine that has good clearances
other than maintain proper oil pressure at low engine speeds
where pressure typically drops.  Any excess volume provided
by the pump is sent thru the return path in the pump either
to the pan or back to the suction side of the pump depending
on engine design just as it would in a standard pump.  There
will be no additional oil forced to the engine above the
volume required to produce whatever pressure the system is
setup for.  A high pressure pump on the other hand will
force more oil (higher volume) to the engine depending on
engine speed.  If the pressure is set too high, even a
standard pump will run itself out of oil if the engine speed
is high enough.  That is why engines that continuously
operate at high speeds as in racing have large or high
volume oil pans or dry sump systems.  You should not confuse
pressure with volume.  A high volume pump at standard
pressure setting will not force any more oil to the engine
than it would get with a stock pump at stock pressure
settings.  Any pump set at higher than stock pressure may
force more oil up into the upper engine running the risk of
oil starvation if the engine speed is high enough. This is
especially true if an oil of too great a viscosity is also
used.

Lugnut