what volume oil pump

No. The intermediate shaft will turn the oil pump wherever it needs to be. Although you can install the intermediate shaft anywhere, I like doing that by the book.

The FSM says to point the slot in the top of the intermediate shaft towards the front most driver's side intake manifold bolt. In other words, when it is in right the slot will be facing about 11 o'clock viewed from above (using the centerline of the water pump as 12 'clock).

The reason for this is that when the distributor is installed, there will be plenty of room for the vacuum advance can to move so that you can adjust timing.