Not exactly a vintage bike but just received my new crosscheck. Since horizontal dropouts were more common on vintage bikes, thought I would ask here and sorry if this is a dumb question.

I am having trouble getting early 90s xt 7 speed derailleur to work in that it rubs against the largest cog on the cassette no matter how the B screw is adjusted. Is there an ideal position (towards the rear, middle, front...) for the wheel/axle on horizontal dropouts when using a derailleur or does it matter?