That's a start. You probably have a steering wheel that isn't centered too as the steering sector is right there in front of it on drivers side. They can move the wheel to center it but count the revolutions to the lock on each side. A half turn difference is pretty bad an 1/8 you could live with.
You could get tricky and measure this out yourself but I don't envy you trying to get that twist out with out a good frame machine. They are very hard to get that Isolated and get the twist out, because it also moves the cross member where the lower control arms connect, this is the reason there are no shims on the other side. It's hard to find a good frame man. A lot of places have fancy machines, but all they do is measure, the frame man gets them straight. Try someone that specializes in frame work for other shops. They are usually a better bet. Then they may tell you what I would.
If you could find a good front sub frame in the bone yard, it might be a good buy, if you want it perfect. If your not far off stick a couple spring rubbers in the left front, and save up for an after market front stub. If your racing it, you could stand to put that Camero front end on a diet anyways.