I am doing a front double A-arm on my 510 for the Solo II Nationals. I have heard of this done twice before, but only saw data on one and they used Mazda components (not optimum). I am starting with Datsun roadster uprights, the Brake Man 10.5" rotors and 4 piston calipers. I am sticking to a 13 inch wheel to minimize rotating, unsprung weight. If anyone would like to share data/experience, I would appreciate it.

Why are the Mazda components "Not optimum"? The one that I have seen and driven uses a combination of Mazda and Toyota parts and works excellent.