They specialize in 2 barrels - with a focus on Strombergs - but have a pretty good selection of Rochester 2g stuff. The online catalog inlcudes a section on linkages and throttle shafts.
Check out your local salvage yard.Alot of older Toyotas use linkage with ball studs.Also Datsun Z cars.Most of the better auto parts stores carry ball studs in several sizes. EvilDr235