69-70 Pontiac only , the Chevy 69-70 brakes are differant. But getting a good set of rotors may be difficult to find. At least with the Scarebird stuff your using more common brake parts. Thats his whole idea behind his kits.
I'll have to double check the measurement between both my 55's on the offset. My parts car still has the kingpin setup. Without having a 69-70 setup to meausure ? I would think it would be the same since it was an option, why would gm have a differant front track width for disc brake cars?