Carb swap, and all the adjustments with it.

Barry Grant carbs have a non-removable site plug. The nominal setting is in the middle of site glass.

The position of the distributor is not relevent. As long as when you are at top dead center on #1 the rotor is pointing to where the number one wire is on the cap and the rest of the wires are in the correct order you are fine.

Instead of pulling the distributor and oil pump drive just move all the wires on the cap over one and rotate the distributor so it's pointing to #1 and you will accomplish the same thing.