I just removed the old Nolathane branded arms due to the bushes getting tired and went through the same realisation that new bushes vs new arms pushed things in favour of new arms. I bought the Hardrace rubber ones just like you have.
If you wind on too much castor you risk fouling the tyre on the plastic guard up front so you can cable tie it forward or even better remove the lower screws holding the plastic guard and drag it forward and re-secure it forward.
Wind on max lock and see if the tyre is scrubbing, if it isn't there is more adjustment available, you should be able to wind more on.