Jim,

Not enough info. Is this full-fendered or a highboy?

Here are some thoughts though.

If you set the axle in front of the spring, it appears that all you have moved is the axle. If the radiator is still in the same place, then you can't move the firewall and still have room for the engine. That means the body can't move forward. If the body can't move forward and you move the axle, the wheels won't align with the body.

That's just thinking out loud using what you supplied.