Good advice above. By merely moving the arms to the front (by switching side for side) you have created "reverse Ackerman". That means every corner you drive around will be scuffing the front tires. A lot of builders, especially first-timers, do this and get away with it, but it isn't a good or desirable situation. It can make handling kind of unpredictable under some conditions, especially wet pavement or intersections that may have dirt or sand on the asphalt.

On my roadster I used an Econoline axle similar to your Chevy van axle. I kept the arms on the back side by heating and bending them down to get necessary clearance. On one of my previous C-cab builds and on the Deuce I am building now I fabricated my own steering arms so that I could get the necessary clearance and still keep proper Ackerman angles. I know it's another big step and a pain in the arse, but worth it in the end.

Having said all that, you can go ahead and get the rest of the chassis fabrication done and come back to the steering arms later, preferably before you drive it.