I think AKWA is the one I've seen the most with a 350/TH400 setup. You can find it (and others) here:

http://www.gearhead-efi.com/Fuel-Inj...Information-4F

Yes, California is primarily for emissions. If you still can't get it to kick down, you'll probably want to go through the wiring. Most of the harnesses I've pulled from trucks with a 400 in them have bad wiring going to the kickdown. Personally, I prefer a separate kickdown switch, I've been using one for years on my Blazer.