First off, I don't see any adjustment to be had in that tie bar setup.

Secondly, my understanding is that it depends on which way you're spinning the wheels. If your props swing out, toe out. If they swing in, toe in. The amount of toe is usually about an 1/8". The idea is to have them become parallel when under load. If you're sitting on 1/4" I don't think I'd reinvent the wheel at this point.