They moved away from the flat arms (at least for the bottom) for the C10's. You can also order them with the "Dodger" upper arms. Take a look:
http://michiganmetalworks.com/store/...product_id=120
I like Porterbuilt because you can get them narrowed with an inch forward to center the wheels. I think you will need to end up modifying your steering with them though.
Have you thought about modifying the stock ones?