Steering Problem - long

I have a 39 Chevy coupe with a Mustang II front suspension. Over the winter months we completely rebuilt the car mechanicaly. All that is left now is the outer body. I bought the car last summer and noticed that every now and then it would dart off in one direction or another on the highway. I knew the suspension was worn out and figured all new parts would correct it. The car has a 235 straight 6 engine and the front crossmember was notched for clearence. They had also lowered the steering rack about 2".
Now that the car has a new floor welded in there is not enough room to raise the driveline to return the rack to it's normal position. I assume what I have is a bumpsteer problem.
Is there anything in the front end alignment that would help compensate?
Thanks,
Bob Warfield

Not in my experience.

Techinspector1 is right on the money as far as adjustments fixing things go.

There's a possibility the M2 crossmember was incorrectly installed and you are lacking caster.

Bad toe-in could make it take off to the side, also.