Have not looked at the pump yet but I nailed the box adjustment, backed the bolts off and tapped the valve up about 3mm and tightened the bolts, wheels off the ground I started the engine and it turned right this time so back under there tapped it down about 2mm, repeat 1mm, repeat 1/2mm and bingo.

All good.

1963 Plymouth Max Wedge
1971 Barracuda