I thought u had a CAV/Delphi pump.. BUT YES, loosen the 3 nuts & turn.. Theres NO arrow on that name plate.. sorry for the confusion..
U want to turn it OPPOSITE the normal direction of pump/engine rotation. {Just a few degrees.}
U COULD remove the front plate & watch the gear move to determine the normal rotation..
OR clean off the np & on 1 of the stampings it will say R-423 or L-423<example, not real #'s.
That LETTER will tell u the rotation of the pump, LOOKING FROM the drive end{front of the pump, looking back}
Just scratch a line..
Take 1 of the nuts back & make sure the mounting holes are oblong & the timing IS adjustable..